
ritsukas fighter is soubi simply because: whenever they kiss during a battle there power gets a boost which only happens when the fighters and sacrifices names touch so there names are on there tongues.
That also explains why ritsukas name didn't show up yet also explains why they thought soubi was a blank fighter just because his name didn't show up too.
And explains why seimei carved Beloved on my poor baby soubi (/TДT)/

soubi doesn't have a name at all, hence the blank. Ritsuka does.
My guess is it's Yuiko.

Lord i pray not
My hole got me here ╮( ̄▽ ̄)╭
Weird enough.