Remember all those half-baked things walking around in Arboria?
They're the result of some experiment gone horribly wrong.
That's been a possible outcome since the beginning of the
Elixir of Eternal Death days. RP-wise you've only been partially
successful in the Becoming, but Bad Things(TM) have happened
in the process. There are several possible outcomes (and don't
get me wrong - it's not a good thing to have happen to you),
each of which leaves the imbiber somewhere between mortal and
lich. I'm currently building a resource with that kind of
information inside (for characters to utilize in the game)
so I'll let you do some research there when it's complete.