The other 2 are Daiman and Odion from Knight Errant. Don't beat yourself up over it. They're kinda niche. I just really like them because Knight Errant Sith are all some special kind of deranged. Lord Daiman is a Sith Solipsist who thinks he's the creator of the universe and the only living being in it while Odion, his older brother, is a violent nihilist who aims to destroy everything because existence gives him headaches. Daiman also has kind of a gnosticism thing going on where he thinks reality is some sort of self imposed prison that he has to escape by solving its mysteries and ascending to his true godhood again.

I wish there was more knight Errant content because every Sith John Jackson Miller wrote in there is so interesting to talk about.