essence has been one of the most controversial topics since the beginning of the beta.  honestly i like where its at now, but i think it needs to be tweaked a bit.

first of all the 1 to 1 ratio of essence to mana should be changed to 2 or 3 mana points to each essence point and reduce the starting amount of essence to 5.  this would give you starting out mana of 10 or 15.  this would allow you to cast spells much more, but give much less of this ultra precious resource. not to mention you wouldn't need to invest as much of this essence into champions to get spell casting ability.

essence should be the games most important resource.  i think that every point of essence should be valuable.  i think that essence spending should be a sacrifice that requires careful consideration.  with it you could do many remarkable things within the game. examples

i think you should be able to add essence to any spell that requires a shard.  by using essence, this would amplify its power by many times.  instead of summoning 1 creature you can summon 10 by applying essence to it.  you should be able to bring a champion back to life with essence, essential breathing life back into them. 

you can use essence to change 1 kind of shard into another.  or maybe even change similar resources into different ones ex. gold mine to an iron ore mine.

i am sure that there are many very powerful game changing things that essence could be used for.  but i think that it should be things that ONLY essence and not magic be able to accomplish.