INT 24 is not enough to predict an exact sequence of events.
So that outcome is not mostly what that person expects to happen. He's not going to show up with an army unless Carissa manages to call him about that, or signal him in any number of possible ways. There's all kinds of possible ways for Carissa to escape once Mind Blanked, right? Probably the tropes will be with her.
If the only result of things playing out like that is for Carissa to break with Asmodeus, but find herself with no clever options besides confessing the fact to Cheliax before they Detect her thoughts about it, they'll presumably employ her the way Asmodia was employed, or put her into storage to trade to him. In this case they no longer have a high-level ilani augment of their own to oppose him. That isn't his optimally desired outcome, but it's an improvement over status quo ante.