For this I've always favored an arcane shapechanger that assumes forms or aspects of forms of creatures from other planes – the self-buff specialist; Tenser and his Transformations.Tony Vargas said:I like the concept of roles, but I don't really see why any must be unsuitable for a given power source.
Oh, Arcane Defender: I suppose you could go some sort of 'mystic knight' route with this. Or, you could have a character who's magic transforms him into super-durrable combat forms. Or an Abjurer who uses wards to protect the party, powering them with his own vitality - he wouldn't stand in front and take attacks, he'd let anywone who wanted to stand in front, and take the attacks aimed at them. Arcane magic can prettymuch do anything, so it's just a matter of coming up with 'spells' that defendery things.
Since I favor it, it means they'll never write up such a class, so that's as close to existence as it'll ever get. But there it is!