Its cool, I would just use him initially to build a few town's then horde him in my capital, thats what I usually do in these game's hes like your king in chess, hes mostly useless, but he can get you sometime's .

As I mentioned in a similar thread any single variable in the game which decides whether someone wins or loses should be a game option.  Thus a diplomatic victory should be a game option... a quest victory should be a game option... the game automatically ending after 100 turns should be a game option... a sovereigns death equals losing should be a game option. 

Certainly I can see moments where I'd want to play a game where I can keep playing after my sovereign dies and vise versa. 

But when you design the Sovereign and his different options, you cannot be balancing thinking: "What happens if in turn 1329, the Sovereign loses a battle against a Dragon NPC and loads the game?". The only way to prevent players to abuse the Load function is to not allow it and have the game autosave each turn, offering you that savegame whenever you want to load that specific game. And that wouldn't prevent people crashing the game or something during a turn to avoid some bad results in the current turn and get the still good last autosave of the previous turn.

I understand what you mean but balancing the game according to a Load function sounds quite wrong to me, therefore I consider it unimportant to consider. In multiplayer people won't go cheat loading and in single player... well, it's single player. If someone feels like he must load the game every time something doesn't go well (be it because of Sovereign or because he lost a city to a Dragon or he changed his mind about the strategy he is using) let him. There is no ripple effet in that.

I consider much more serious the threat of the AI not being able to handle correctly the Sovereign (be it playing carelessly with him or not using him to his full potential). This would be one of the reasons that would make me reject the Sovereign as a unit. And would make me very sad too because I love the idea.

Hopefully I explained myself better this time?

And NTJedi is right about having the Sovereign Death as an option. I would have it always checked (as I do have Super Events in Gal Civ II) but it would be nice to be able to disable it for those not interested the same as with the victory conditions.

As a practical matter, we would probably let players have their cake and eat it too.

That is, an option for "hidden sovereigns".  

In this mode, the sovereign only becomes a playable unit in the game when the player wants them to and the rest of the time is simply "hidden" somewhere and is untouchable.

A la Netstorm: you have a priest(game over if dead), but when lowered to 1 hp he becomes immune and immobile and cant do anything, he then can be picked up(captured). The player can then build an altar, and using his own priest(sovereign) he can complete a ritual to kill the enemy priest.

Implentation: when " killed" sovereign is immobile and invulnerable , no magic no bonusses. He can then be captured and taken to enemy capitol, where he's ritually killed.

If he's incapicated, he can't do anything and needs to be healed or he regens slowly himself. Another option would be that he has to return to his captial/big friendly city and be (slowly) ritually revived, maybe with some extra costs as well(essence, xp) . This means that getting your sovereign killed in your own borders is not good, but not gameending since capturing him back and reviving can be done a lot easier in your own base. 

However, outside your borders it will not only be harder to capture him back(less bonus, and reinforcements farawaY), if you succeed it will also take a lot of time to get him back to your capitol too.

Simple, give a Soverein a Very high Withdrawal, aka, if he is not the lone actor, a native 50% withdrawal. After-all, in FFH, people are learning that 90% withdrawal can be a very powerful thing .... units teleporting over mountains and oceans even due to "withdrawal" ... but I digress.

I agree that its perfectly fine to have a mortal Soverein unit. Adds to the "realism" of the game in a way. Also, sometimes multiplayer games adopt courtesy rules to avoid imbalanced-ness. What you describe seems to be "rushing" which, why stop there, simply destroy their starting city while the soverein runs away! I would say its much moreso "rushing" than sovereign chasing, although it could be a matter of perspective.

Also, it helped in Total War when most "sovereigns" were mounted units with an elite mounted body-guard intrinsically attached to him. (2 hp instead of 1 hp each)

To add to a Sovereign's surivability, when you kill an opposing Sovereign you could gain Divine blood equipment, which gives a one-time usage of immortality, or rebirth in the capital city. (an extra life)

some-how this argument reminds me of a guy talking about how "hard-core" some MMO's were. That if you died you had to start over, or somthing. Although it might have just been that you lost all your equipment and gold (which you didn't have in the bank) as well as a possible experience loss of some-sort.

basically wether we are talking about extreme (forget) -> mid-level Ultima Online -> easy WoW