This Keltham warns her not at all.  He accepts his fate, to betray her as she betrayed him.  Carissa didn't want to do it, but did; and Keltham does the same, because he has children in the Boneyard and sometimes Asmodia screams his name.

He binds Carrissa by geas to honesty and promise-keeping—for he still has great sums that Cheliax by compact owes him, though he negotiated less aggressively in this timeline.

This Keltham warns her not at all.  He accepts his fate, to betray her as she betrayed him.  Carissa didn't want to do it, but did; and Keltham does the same, because he has children in the Boneyard and sometimes Asmodia screams his name.

He binds Carissa by geas to honesty and promise-keeping—for he still has great sums that Cheliax by compact owes him, though he negotiated less aggressively in this timeline.