He set a new record for fastest mentor death I've ever seen in a rpg. He was introduced, bonded with the party, and dead within the hour. On top of that, rather than mourn for him properly, Rex flirts with Mythra first chance he gets while literally standing on his grave.
I mean, I wasn't the biggest fan of the first Xenoblade game. I thought it got pretty bad after the half way point. But this one is wasting no time in it's terribleness.