Okay I never played Guardian back when you had to quest for extra souls but I was wondering about this as an idea for a Defiant.
The Defiant start with "your soul", then later in the noobie area u use a device to absorb the soul of another being (i usually assumed that of a defeated Guardian.) Later when you wanted more souls you had to use a closed death Rift to bring forth the soul of a fallen <insert soul type here> and defeat them.
The RP idea is this. What if it was not just the other persons power we absorbed. Obviously you have to absorb knowledge in how to use the powers but what if you absorbed portions of their essence, their memories, their personalities? The idea is basically an ascended dealing with the different souls now contained within him and trying to reconcile them so that rather than being a split personality they can instead become a gestalt and say rather "We were created by you bigger and brighter and more alive than any mortal could aspire to be! I am we and we are me."
(10 plat to anyone on Faeblight who get the reference in the quote )