I like the bonded villainy. Always fun.

Betrayal this would probably be better if it included Indifferent targets as there is a certain trust to ignoring someone, othersiwe it's being unfriendly. Makes it more useful and you can imagine a fight starting with one of those knuckle knives cutting a gash in the victim's face and him holding his eye in disbelief.

Ceremony of Becoming the male version should have it's breath weapon more often, at least once per encounter, if not once every 5 rounds [i know that's more or less the same thing in core, but whatever], otherwise it'll become that "incase there's a bigger robot crab later" situation like with special guns in video games...

Pact of Ignorance there's something about this that doesn't sit right with me and I can't place it. Might be the seeming selflessness on the part of the Rakhsasha...

Ceremony of Flesh Again, the male portion is a little weak. Regeneration 10 would be more like it, otherwise it has no combat effect at these levels save for making it impossible to keep him down [unless that was the intention, in which case Regeneration 0 would be sufficient]. The regeneration should be overcome by something symbolic, perhaps Good or even Sacred... Then again, I've prefered the Pathfinder/4e version of Regeneration since they emerged anyway.

Darkness O'er All this should probably be once per encounter; once per day capstones are a pain and at this level, you need every aid you can get against magic. SR might be in order if they expect betrayal at all points too.