Shame...I didnt even get a chance to start.

Blackthorn spends another lonely night in the Tavern nursing his ale.....

In the First edition/Second (?not sure) PHB Raise Dead did let the undead become living again if they were "newly created" and fell within the 1 day/level time limit. BASIC rules state otherwise. Interesting though....just thought Id say because i have my old PHB right by the computer. Is...

Raise dead and speak with dead work on the dead, not the undead. Undead is a distinct state. In the First edition/Second (?not sure) PHB Raise Dead did let the undead become living again if they were "newly created" and fell within the 1 day/level time limit. BASIC rules state otherwise. ...

I wouldnt allow it either. Once you are changed, thats it. Cure disease wont work. Its like in the Walking Dead with Herschel keeping Zombies around hoping for a cure. they are dead, changed, irreversible now. (maybe Limited Wish or other powerful magic)

I always think of the "Warhammer" type Witch hunter...

Templates can come in handy with themed encounters. Lair of the Frost Giants?
Frost toads! Ice bats! Snow wolves!

Like a template you can add to another creature or races stats? I think 3rd ed D&D had something like that. It will be neat to see what you come up with.

I dont know if thats really necessary- but its your project. You can say that the planar half is dominant. You dont choose the other half-traits for other Half breeds like half elf, half orc, half ogre , etc. But im very excited to see what you come up with.

Reading:
Military history- Anglo-Zulu War 1879 , Rorkes drift, other battles, fascinating stuff.

Listening:
Red Hot Chili Peppers

Watching:
Breaking Bad, awesome show. Gun Glory- old westerns.