Same Character, or Polar Opposites?

I'm trying to figure out if my three active player characters in various RPGs are really the same characters, or if they really are opposites. I didn't set out to create similar PCs, but now I'm starting to think: what am I really trying to play?

Ezra L. Pyreborn - an undead mage in the World of Warcraft d20 game. I've long been unhappy with D&D's straitjacketing of characters into race/class/level brackets, and the chance to play an undead PC was compelling. Aside from that, the Forsaken are very interesting culturally. He is sinister and cunning, but ultimately he acts out of feelings for his lost wife and child.

Experiment 36 - a clockwork shaman in a proto-steampunk setting. He is a spirit inhabiting a mechanical body, and is the property of the University that sponsored an upriver expedition into unknown northern lands. He is selfless, compassionate, and sometimes fatherly.

Windwalker - an urban shaman in a Snow Crash-inspired cyberpunk game. He began as a character to support the magic system I wrote for the setting, given the GM's specific requirements for integration into the setting. He's a desperate criminal and drug addict, with respect only to those also addicted to the mystic drug that empowers him and to the spirits with which he deals.

While their personalities differ, there are similarities of detail. Ezra and Windwalker are both members of a secretive order of outcasts. 36 and Windwalker are specifically shamans, while all three are magic users of some kind. All three characters have partial amnesia.

Neither Ezra nor 36 eat, drink, or age; they're not mortal in the conventional sense. Both characters are also physically malleable - Ezra because of ancient ur-Scourge shapeshifting magic, 36 because he is physically a machine and may be rebuilt for different tasks.