Well excuse him for having reasonable trust issues with a guy that controls a group of beings called Assassins, and that has a history with stabbing his own people in the front.

Riku keeps quiet, head turned front until they finally reach Roxas' pod. He just nods at it in acknowledgment of Sora's Nobody, then takes a step away to allow Axel closer and turns to leave.

They may be enemies, but that doesn't mean Riku won't grant the other the privacy he deserves for this.