Past Lives/Alter Egos Taking Over in Scenes

[AfterCrescent]

I'm prepping for a new game for some players and am trying to figure out the best way to make this work.  Long story short, all the PCs will be mortal incarnations of some elemental/natural/primal force (air, trees, rage, etc).  Unfortunately, due to Far Realm intervention, they don't know they are (the players, of course, do) until something triggers the release of the spirit/force.

Think Avatar-state in Avatar: TLA, if you've seen it.  The game will be run in 3.5, and I'm looking for ideas for how to handle the mechanics of the alter-ego taking over when it does.

Eventually, I want the players to be able to coincide and/or conquer the spirit and have control over the power granted, but I'm not sure what those powers are/how they would work, from a mechanical standpoint.

Any ideas or suggestions are welcome. Thanks. 

[Arturick]

Have the characters build a character, an alter-ego character, and a gestalt of the two.

When their character first have their "flashbacks," they put aside their character and use the higher level alter-ego.  When their character level catches up to the alter-ego, they "gain control of their past self" and switch to using the gestalt character.

[sirpercival]

dman11235 has D&D3.5 Avatar rules posted in the homebrew forum, if that helps...

[Prime32]

Follow the example of the Frenzied Berserker? The first time a PC unlocks their power, they go berserk and start attacking everyone with it. They can attempt Will saves each round to get back under control.

As for the powers... at-will domains?

[AfterCrescent]

Have the characters build a character, an alter-ego character, and a gestalt of the two.

When their character first have their "flashbacks," they put aside their character and use the higher level alter-ego.  When their character level catches up to the alter-ego, they "gain control of their past self" and switch to using the gestalt character.

Oh, I like the idea of a second character.  I think the arbitrary level to match is a little wonky.  I was thinking more like a power that they turn on/off when they gain control of it. Probably with some form of drawback, but I'm not sure what kind.

The gestalt when they gain control of it sounds like a powerhouse, which is awesome. It may be a gestalt game already, so that might complicate it, but I like the potential here.

dman11235 has D&D3.5 Avatar rules posted in the homebrew forum, if that helps...

Thanks. I read through those briefly and didn't see any rules for the actual Avatar and/or Avatar state, though. :/

Follow the example of the Frenzied Berserker? The first time a PC unlocks their power, they go berserk and start attacking everyone with it. They can attempt Will saves each round to get back under control.

As for the powers... at-will domains?

Domains would probably work if the spirit/force they choose is easily defined as one of them. Hadn't thought of that. Were you thinking both domain power and spells, or just spells?

[TiaC]

This reminds me of a game where we generated 4 sets of stats, then each built a character for each distribution. We played as a set of personalities rotating between quadruplets. The DM had a system for switching us that was partially controllable and partially random. Notably, whenever a character was rendered unconscious they were shunted to a random body, unseating the next to be randomly placed until someone ended up in the empty body.