I considered starting a new thread, as this is going to be a fairly large post and I don't want it to get lost in the larger thread. But for now I will post it here.
We have two opposing and important interests. On the one hand, if channeler death or fight lost = game over, then no one will want to risk their channeler. On the other hand, if the channeler is incredibly difficult to beat, and there isn't significant cost to losing a battle, channelers will just wipe out armies, and if they lose they will just recall and pick up where they left off.
I think one of the problems is that many of those who are against channeler death being game over are looking at it from the perspective of they are the channeler that got defeated. Look at it from another perspective: If channelers ARE these incredibly powerful forces, and you manage to defeat one, wouldn't you just be incredibly pissed if he just reappeared back at his home town and resumed massive destruction of your armies?
I agree that the channeler losing a battle that he is at should not be the end of the game. I would propose that the channeler does not die in a lost battle. There are many ways to handle this. many of which have been proposed in this thread. I also think that the defeat of a channeler in the battlefield should be a huge victory for the player that manages to do so, and a huge setback for the defeated channeler.
I DO believe that there should be a condition where a channeler can be utterly destroyed and that be game over for that player. It would NOT be a VC for the winner (unless they were the only two surviving players at the time).
An idea that I had that I have not seen posted yet:
Each channeler has a wizard tower or equivalent like MoM. This tower or whatever could only ve in one of the towns that he possessed, but could be moved from one town to another via a spell.
This tower should give significant defense benefits to the channeler when he is occupying it.
When a channeler falls in combat, his corporeal form is teleported back to his tower - always.
His "spirit", "essence" or w/e needs to travel back to the tower. It is invisibile and un-attackable, and can travel thru ALL terrain squares. It should be one of the fastest if not the fastest unit in the game. But if it had travelled FAR from the tower (across the world) it should still take significant time to return.
Until the spirit returns and reunites with the corporeal body, the player is in a Sauron state (as he was during the LOTR trilogy). He cannot cast spells himself or imbue or do anything directly, however he is still able to control his troops completely and exactly as always. His cities and armies, heroes, etc remain his. He just cannot take direct action until the spirit returns.
Possibly there could be a spell that could make the spirit return instantaneously. If the ability existed at all it would have to be cast in advance and incur a significant ESSENCE cost.
When the spirit rejoined the body there should be some or all of the following:
Current Mana at zero (you would need to recharge your batteries)
Weakened physical state for x turns
Significant essence cost - in other words, if you did the "Immediate Essence Recall" described above you would be hit in the Essence TWICE.
In order to permanently kill a channeler one of two combinations of conditions would have to be met:
1) You defeat the channeler IN his tower, or
2) You destroy the tower during the period when that channeler's body and his essence were separated.
For either of these to occur, the defeated player would either have to make multiple huge strategic errors, or he is for all intents and purposes out of the game but is just to stupid to know it yet. If the channeler's tower (or whatever) is destroyed while he is in the field, he would have the ability to cast it in another city the following turn, possibly a small essence cost for this.
Whew. Sorry for the long post.