True, it's possible abandon psionics entirely (although it would leave open a niche as none the sins are psionic). But it would be harder to determine what spell-alike abilities you got as unique devil then. As even at 12 HD you should have a lot (assuming you go for advanced outsider HD instead any class levels then).<br/><br/>I would myself prefer if you keep psionics as it gives clear idea of her abilities and thrallherd is awesome PrC for her (she gets minions who are ready sacrifice themselves for her and they are easily replaced). Also yuan-ti abomination which she is based off on is psionic creature.