Agent of Death Character Build/Race?

[Kerrigor]

Okay, so I'll try to keep this simple.
I am playing in a 3.5 game, Forgotten Realms universe, extremely high power game. (We will be gods at, if not before 20th level. We will be killing gods. Gods will be trying to kill us. At second level, everyone already has multiple magic items. These are characters who pretty much have their patron god(dess)'s protection.)
However, I am playing a character who may die. Because he is a tank in a party of mages. Like, the only tank.
So, in the event that he dies, I'd like to have a character to replace him.
I'm thinking an agent of a death god, wields a scythe, black robe, so on and so forth. Not evil, but more of a neutral character. A "When it is your time to go, you must go," type thing.
So I've got a really cool concept, I think, but no idea how to do it.

Creation details:
3 18s, 3 16s, then add racial bonuses
We get 1 extra feat, and an extra 13 skill points.
We get one masterwork item, and 200 gold
Gestalt
All sources allowed, psionics discouraged (but if it's really cool, I think I can swing it)

[ATHATH]

There's a Druid variant with pretty much that exact flavor. It's called Reaper of the Wilds or something; lemme find it.

[ATHATH]

Found it!

It's called the Wild Reaper, and it's from Dragon Magazine #311. Highlights include innate access to Turn Undead, passive ability score regeneration (feel free to cast as many Sanctified or Corrupt spells as you want (well, as many as your regeneration can handle)!), and access to a few additional spontaneous spells. Oh, and you still keep Wildshape and your Animal Companion, but you're limited to carnivorous animals (and, for wildshape, omnivorous animals that feed on carrion as well). Oh no, I won't be able to have some stupid herbivore as my Animal Companion instead of an awesome Fleshraker! Oh, the agony!

Don't forget to pick up the Dead Levels and Domain Druid ACFs if you're in a high-OP game, because they cost literally nothing (in game-terms; out of game, I dunno). Check out eggynack's Druid Handbook as well; it's really good.