TL;DR
He/They

Mykhailo is a character/costume designer that comes from a family of scholars who researched Darkrai over the years. While he was originally uninterested in this research he later attempted to catch Darkrai, failing and passing away. Years later he would get revived by Dialga, where he ended up reuniting with an old friend and joining Team Galactic at their offer as a job. Now he worries about what happened with Darkrai after his death, as he feels like something else bad must have happened.