So... what Mom-based superpower upgrade is going to solve this? Hot cocoa?
I actually hope it's Rick and Laura defeating him, with the rest of the party arriving and acting as support.
Rather than Kachua simply solving everything, this is a moment of growth and development for Rick & Laura as characters on their own, and with shared history. They both have leveled up and grown as people, so confronting the past like this and "settling things" feels like the appropriate line of action.
Kachua can come in and be a grounding force for Rick if he starts losing it, but I'd prefer if she not fight his battles for him.