here is a detailed compendium on all sovereign and their strenght/weaknesses and playstyles
i based my evaluation in different phases of the game (early:lvl 1-5, mid:lvl 5-10, end:lvl 10+) using the more intuitive role playing way of using them
LADY IRANE
role: ranged assassin
skills:
-hunter is a good trait, help her early but becomes less important mid and end game
-tarth blood is perfect for exploring and leveling, helps her to hunt around in a small party like sovereigns usually do
-starting spells are just decent, most times you dont really need them though
-impulsive trait is also nice
-master scouts is really great and defines the race, being able to explore freely and position piooners early with no risk is huge bonus
-archers is another great trait, once you have access to these bows your army is really powerful and you have an amount of dmg really high
-masterwork chainmail pretty useless i must say, doesnt help much
early game:
irane starts with a bow and her overall early is not that bad, being ranged helps when opponents have no defense and low hp and also dont hit much, most of the times they die b4 reaching you or just hit you couple of times
but still her damage is pretty low, and she has not much utility to her team, its probably still better to wander with a couple of mates, either champions or summoned pet or anything because otherwise she cant really kill everything low level, just a big pack of wolves or spiders can be problematic
the best thing is you can snowball more than others placing many cities early without any risk, this is 90% of her strenght
7/10
mid game:
here irane starts being really weak and fall behind, as a fighter she has absolutely no damage compared to others, she ofc hasnt tanking capabilities and her early assassins traits arent really strong
unless you have been lucky finding a very good bow as a drop irane is basically useless, you kill medium monsters you really need a strong tank champions and some real damage
this is a huge problem because you cant rush the research into bows so either you have lvl 9 champions or you are closer to research the final bows ( Very good)
one way or another your mid game is bad, you need to stack criticals traits b4 doing any dmg and need to research a lot of thing
still the only good part is you should have a high research having built many cities early
3/10
end game:
in the final part of the game irane is good again finally
you have access to rams horn longbow that is quite a cheat in your army, a good party of those archers can kill basically EVERYTHING from monster to strongest armorer sovereigns
irane herself should finally have a good crit chance/dmg and maybe you foudn some book/item meaning now your crits WILL hurt, they are still a bit nerfed but adding you should have very high initiative irane damage is pretty good
the problem is still that end game depends on mid game, if your enemies farmed all the quests/monsters you couldnt kill you are still behind, if they declared war in mid game you are probably still in trouble etc etc
7/10
suggested fixes:
irane is not bad but overall she needs a small buff
my suggestion would be changing masterwork chanmail into something early game, something archerish, like a improved leather giving some initiative or some tools like rings amulets for hunting
anyway something that would buff irane and her army dmg early mid game, not requiring a lot of research because irane has the tools but all of them happen too late, she need a early research that allows her to resist mid game when the best research come
LORD MARKIN
role: tank warrior
skills:
-ironeer blood is very very strong a huge defensive trait to a sovereign already so strong
-starting spells are SO INCREDIBLY STRONG, he has basically EVERYTHING a tanking support need from life and earth schools
-hardy like it wasnt enough all hes got another hpxlvl trait summing that to 30 spell resists and immunity to poison
-train golems is another decent trait
-armorer is another OP trait giving 25% defense bonus that scales really too well end game
-master smiths is a good trait but not so important because all the others are so OP even this good trait doesn shine
-great hammers, another good trait offering good weapons but even here being the sovereign so strong he wont need them, but could help his army
-light plate, about the same as above, helps slightly the army but its not much relevant
early game:
the empire itself is the only problem just for the reason he has no particular tool for that
this is more than balanced by the strongest sovereign in the game by a long margin, lord markin early can literally STEAMROLL EVERYTHING, not only small creatures but even some medium at early levels
that is due his incredibly scaling and snowballing power making him gain a huge amount of defense/hp with few levels AND the nature summon which is very strong
basically he can kill 90% of the monsters the remainin 10% being able to be killed thnx to the summon
summon is very OP the only con he has is the HUGE mana cost but even like this since he doesnt really need to cast often its not a problem
10/10
mid game:
here markin starts becoming a beast, you probably have another couple of hp traits and some dodge and so high armor he can easily tank and kill medium monsters no problem, against strongest ones he can still get the summon help and very strong spells like stoneskin heal to support etc
he is just a beast in fight
at this point you also start getting some reasearch into more fighting tools like the unique items and probably since you never fear monsters you got some good drop out there
i usually take few points into some offensive trait because he is totally unkillable by his peers so maybe taking path of the warrior or assassin is a good choice, but you can still focus on full tank and get some more dmg from other champions or army
10/10
end game:
he is just GOD
not other words, at this point of the game you surely have found a good weapon meaning you can deal some dmg while still being nearly unkillable, add to that some armor drop or champions gear et voila' the best tank in the game, he can blow dragons and enemy sovereigns cant really hurt him in any way, can solo cities with full defense no problem
ofc the real advantage here is that he can kill EVERYTHING, meaning your opponents are starting to struggle facing dragons etc while he can wander and farm the strongest monsters that gives 1/3 of the level each meaning he can keep leveling while his opponents are slowing down
but its irrelevant, he can kill the final quest boss way sooner than lvl 15 but he could also take any city he wanted to
10/10
suggested fixes:
he surely need a good nerf, first id remove his summon because that combo really makes him unstoppable early, imo there HAS TO BE something he cannot kill
then maybe id lower his damage or his scaling i think too many hp per level AND 25%defense AND spell resist is just too much
maybe some less base initiative and accuracy
MAGNAR
role: pure mage
skills:
-warlock dmg is a base for every mage, good skill ofc
-irrelevant and pretty weak in the actual meta because magic is too weak so its useless to have resists at all
-starting spells are just what he need, fire nukes, but his set is not really so huge
-attunement some more mana helps mages ofc
-brillant, this is a good trait, a must for mages ofc and helps level up
-train slaves, so and so trait, slaves help but usually you dont really need so much them, but as cannon fodder it helps
-slave lord this is a very cool trait totally changing gameplay, he really HAS to focus on fighting and killing enemies to feed his empire
-flesh bound tome not so strong imo
early game:
he has a small tool set but very effective
as any classic mage his power is really high, being ranged he basically can kill everything providing he has enough mana, which early on cannot really be possible
but he has another toolset with racial traits to use slaves to fight cheap and regain mana
its not really needed 90% of times imo but its a cool idea overall
9/10
mid game:
he is a bit "luck" dependant, because magic relies a lot on shards
prividing you have some and research the improvements magmar as fire mage just become GOD
his offensive power is immense and way below lvl 10 he can already kill really nearly everything in the game, most times just 1 shotting
being very lucky with shards and level up traits its game over here, no one can really match his power and even being unlucky his damage is anyway very high just not godlike
10/10
end game:
magic is scaling really too much in the game right now so if opponents really manage to get to end game its over anyway, you will have all the best traits and probably managed to find many fire shards making your damage immense
also your spells would cost not much thnx to traits so most likely you wont have mana problems
this is a major flow of the game, you dont really have to be glass cannon, wearing some heavy armor and shield is totally possible and the penalty is about nothing since the dmg comes from shards you can just be a half tank cannon but its not really needed because nearly no one at this stage can even touch you
10/10
suggested fixes:
magmar himself needs a small nerf but also is about general game mechanics, spells shouldnt scale so much, ppl around you should have much more spell resists etc
also to notice in this actual beta ai movement is broken so often they take more turns to reach you, greatly favoring ranged combat and so magmar
as a final notetraits providing dmg shouldnt be so huge at early mid levels
EMPEROR KARAVOX
role: tank mage(i think atm this is the most indicated role for him cause of the abilities giving him good defense, but having 2 powerful schools of magic i think its best being a bit mage too than a pure tank)
skills:
-diplomat its quite impossible to estimate in strenght but should help keeping the peace and so maybe favors a defensive expansionist/explorer gameplay
-krax blood pretty good defensive skill with fortify being the MOST BROKEN SKILL IN THE GAME, seriously is something not even remotely thinkable, 30% dodge for free , seriously???
-wealthy another pretty good skill that synergize a lot with the recruiting both factions champions
-starting spells are quite good
-defensive is decent but you really cant win just defending your own cities, so dunno, probably its strong in ai hands but as a player i dont think its so good
-betrayers is over all nice but in the actual game quite useless, the game doesnt favor hiring MANY champions, just a few good is the best option
early game:
he really doesnt have any good toolset, his playstyle should probably move towards expansion/exploring but there isnt really anything for empire and only thing sustaining him is how OP is fortify
so if you luck with fire shards early you can just build him full mage maybe otherwise even a tank that can occasionally cast works imo
anyway he is just a nerfed copy of other sovereigns, doing many things none of them any good apart from abusing fortify which ofc make him a decent tank
4/10
mid game:
again there is nothing in his toolset to excel
probably the only thing keeping him competitive here is if you rush research champions and hire the best in the world
but again, having many champions is not useful, and hiring all the good ones cost really too much early mid game
diplomat bonus could keep the peace to keep going to quest and exploring and so maybe keeping ad edge in items/levels over the opponents
but still the base is a weaker copy of other sovereigns
also unless really lucky with shards now the dmg starts to lower, no base bonus to dmg or mana, nothing to keep him competitive, ofc apart from fortify that until it gets nerfed allow him to play
3/10
end game:
here the possible paths to victory using his toolset appears to be research or adventuring
he can abuse the defensive bonuses while doing this other stuff instead of war while keeping the peace the longer possible
but still he has no peculiar bonus to neither research nor adventuring so he should still fall behind opponents
2/10
suggested fixes:
well i assume fortify will be severed soon, at least a mana cost and way less dodge is needed but id also make it last few turns not forever
so then apart from abusing this mechanics with ai he would just need something for his expansion but in general his playstyle is lacking, could really use a totally new skill to improve him someway
ORACLE CERESA
role: mage summoner (i focus on shadow magic just cause it seems more appropriate)
skills:
-summoner is ok ability and also the mark of the sovereign
-wraith blood im not even sure its a buff, it seems more a nerf to me 
-starting spells are really weak, the worst for every school apart the summon ofc
-attunement just the usual help for pure casters
-scarred another huge nerf, she really has low hp
-adepts is really a minor buff, a small amount of mana to help her start and a tech that doesnt require much time to get anyway
-death worship should characterize the sovereign but imo is still a bit weak atm
-binding is a really cool skill offering a whole new set of creatures
-no armor is another huge nerf to compensate the quality of summons and creature she has at her disposal, over all the sum of all nerf is too huge imo, dying is too easy
-staff of souls is a very very good starting item, as soon as she has a good nuke it really helps
early game:
she is decent fighter due to her summon who helps her to kill stuff she couldnt due to lack of nukes but the scaling is veeeery slow, and having such a low survivability its quite hard to play a glass non cannon
creatures i saw till now also arent that strong, spiders dont quite offer enough to progress fast and her many curses are pretty useless apart a few situations
5/10
mid game:
she really start falling behind as a caster, shadow school is really weak, so unless you luck a lot with shards OR you abuse her background going fire etc she is pretty weak
nothing else she has really helps progressing here, she has half attack mage traits but no nukes and summons really fall behind fast after lvl 5
there is nothing to cover the gap
2/10
end game:
i never really managed to win a game with her at higher diff so this is still WIP
i dont see anything that gives her a chance tbh apart some very lucky start and resource placement
suggested fixes:
summons really need to scale someway to follow her in her progress
not her problem but spells arent balanced we really need improvement into air death earth schools
her unique creatures should be buffed a lot
LORD RELIAS
role: warrior (he is a bit a jack of all trades but since he can craft nice swords...)
skills:
-adventurer weakest skill in game, really lvl 2 takes 2 fights... just useless
-altarian blood decent skill synergizes with his adventuring role
-starting spells are pretty weak
-natural leader instead is really OP but the metagame doesnt really points towards recruiting much, its still better recruit than not 
-train henchmen, like you didnt have enough champions 
-wanderlust is quite meh, athican leather is pretty bad and the sword comes really ages too late, so its pretty useless
-heroic decent to help progressing thourgh quests
early game:
he has basically nothing, just nothing, he is basically a weak warrior, only good thing is early is fast starting lvl 2 and leveling quite fast, just 2 3 quests and few mobs and you are done
3/10
mid game:
he basically disappear, he has nothing to grow his empire, nothing to defend it, all good techs comes too late, the only interesting concept is henchmen but they come waaaaaay too late to be of any use, considering you already have real champions... if at least you could rush henchmen way faster maybe...
his strenght as fighter is just nothing, the only point in playing him is hoping to find a chain of easy quests to farm and mobs you can defeat, and farm them hoping to get the gear to snowball
there is no other way to progress, his only strenght is leveling faster, but he has no tools to level against the right monsters... he can just hope to not find them but keep finding weaker ones
2/10
end game:
just slightly better because you can do repeatable quests to get good items and you bonus exp should matter, but all other relias skills arent really useful
3/10
suggested fixes:
he really need some fighting tool to be able to use the bonuses on questing and leveling up
also all his unique items and henchmen NEED to come really early in the game otherwise they are pointless
WARLORD VERGA
role: warrior
skills:
-warlord actually useless skill since gildar arent really a problem
-trog blood, pretty weak
-starting spells are so and so, you need to invest into spells if you want something useful to cast but blindness is very good
-hardy as usual a great trait
-train juggernauts well they are really op and gamebreaking imo
-warriors so and so starting tech
-warrior cast might help when rushing your army
-great axes arent so great tbh
-no ranged weapons quite hurt, having everyone melee isnt that great in this game
early game:
as a tankish warrior he can handle some stuff, death spells are quite good as supporting him (blindness mostly)
rushing an army seems the only viable strategy while rushing juggernauts are research since they are game breaking
he can survive early game without shining
6/10
mid game:
here his power starts to fall a bit behind, you either have a very good starting locations with many spot for cities or its nearly impossible to be on par
as a fighter he is just a decent tank but needs good gear to progress and you cant have yet all the good traits
but sooner or later juggernauts will come, its just a matter of how much behind you are when it happens
(ofc this works until ai figure how how easy it is to counter juggernauts)
4/10
end game:
abusing ai with an army of juggernauts can give you the victory but really he has nothing else to offer, his toolset falls behind the more the game progress
and as a pure strenght the sovereign isnt on par with others
4/10
suggested fixes:
as other sovereign the items need to come waaaaaaay faster to hand, its totally useless to have medium weapons that comes... mid game, either you have them soon or they are useless just offering not much more than usual weapons do
his base skills need some rework imo to make him better
i also hope magic will get rebalanced making his early death spells more useful
a smallish buff early game could really help progress in his path and making him a viable choice
QUEEN PROCIPINEE
role: summoner mage
skills:
-amarian blood, nice passive bonus
-starting spells are pretty bad imo, apart from the summon she has not good support stuff and no DD spells
-attunement, the usual help for casters
-adept is not so good tbh
-enchanters is pretty weak as unique ability only outposts might be useful but just to save time nothing more
-scrying pool is pretty OP since essence is now really strong
early game:
she starts quite well same as ceresa thnx to the summon, also scrying pool is a super good free essence, she has no problem at first levels and she is quite good
8/10
mid game:
and suddenly she become nearly useless
none of her schools of magic are any good mid game(well not her problem just as usual only fire is viable in the actual game)
summon is totally useless, it cant tank anything meaning you need a real tank, but he doenst do any dmg either so its just a waste of mana against mid creatures
only option to progress is taking the OP schoools of magic providing nukes but that is just going against nature, she ISNT a nuker
enchanters is totally useless now because you most likely cant defend your cities from monsters growing
scrying pool is the only joy but since your cities are gonna fall anyway its pointless the small early advantage is gone
3/10
end game:
well there isnt any, as usual the only viable option as caster is going full nuke on some exploited school of magic and having many shards, otherwise youll need other champions or a good army to fight while her watches from behind sadly
2/10
suggested fix:
as other casters we really need improvements in the not working schools of magic and better summons
enchanters abilty need to be just remade, this version isnt any good