fromfiction:

It’s simply one of those inevitable vagaries of terminology.

There are 25(ish) souls (system members) sharing this body. Each of these souls is an individual. Each of these souls is part of a large, intertwined cycle of reincarnation that we are caught in together.

Each of us has lived through a number of incarnations– fictionkin lifetimes, in which we were incarnated together and interacted during that lifetime.

Each individual system member is fictionkin, and has their own kintypes. Experiencing a kin shift to that kintype makes them a fictive of that person.

For example, some of the lives we’ve been incarnated in are Homestuck, Danganronpa, Marvel, and Ace Attorney. So each member of the system has a kintype from Homestuck, Danganronpa, Marvel, and Ace Attorney. Vriska Serket is Toko Fukawa is Sabretooth is Klavier Gavin. 

So when we’re talking about being fictionkin, we say that Toko Fukawa is one of Vriska’s kintypes. And when we’re talking about being plural we say we have a Toko Fukawa fictive.

Does that make sense?