I actually can understand why Kaito wouldn't care about his match with Yuma. He has only dueled for Haruto and now that he's safe, apparently, he doesn't feel any drive to duel. The fact that he's exhausted from his Photon Change probably doesn't help. I think it's too late to make him feel guilty for stealing souls since that hasn't been really focused on outside of his debut. I'm not really into the duel so far and Yuma's happiness annoys me so much for some reason, but maybe it will be more interesting in the second part, especially when they'll apparently have both versions of their ace monsters on the field at the same time. I'm not sure how that works though.
I was glad to see Tron was alive, although it would have been nice to show his reunion with his sons. III's name fits him very well and IV's name works too, although it is always weird for me when a character in a show I watch has the same name as my older brother. I'm sure that they'll appear at some point in the next season