DarkMatter: Hey, I used Renny first. In my first IC post, to be exact.
Loth: One consciousness with two halves: female (Renny) and male (Renton). Each half has a matching body, but the total consciousness gets shoved in one body at a time. They flick back and fourth after prolonged time in LCL/Synching with the Evangelion. When "straight", one personality does most of the talking and the other acts as voices in the other's head.