"Wasn't even slightly considering it. Off with you, you need to talk to some of the people correctly relying on you for salvation, non-Good person."
(Notably missing from Carissa's compact with him: a specification saying that, if he does release Rovagug, Carissa shall not at this time be prevented from escaping to Elysium or the Maelstrom. Both of those planes are supposedly infinite, and the Maelstrom in particular is supposed to ultimately head off into the chaos outside Pharasma's bubble; which would make it much more likely that you could escape Rovagug, starting from there.)
(He's not suggesting this clause, if she hasn't thought of it; because Carissa might, at that point, demand that clause in order to not fight it out with her own self-image, which clause would then potentially hamper her actually saving the multiverse and also force her to think of herself as a worse person. It's just funny because, Carissa's real emotional priorities being what they actually are, she obviously hasn't once thought of it.)