Sidekicks do have comments on Ukaizo but they don't talk to the big guy. They also have comments in the DLC even if they aren't a recommended companion. I was pleased to see even Mirke had a few comments in SSS, and the arena guards have barks depending on what sidekicks you have. Ydwin has a lot of say in FS. I recommend Vatnir for SSS as well, he has a lot of funny lines.