If you had the ability to run faster than a vehicle that can dive between the imaginary space and have a fuckin’ rocket launcher, would you not want to fuck with a bunch of kids that went and destroyed an entire timeline you were just in for shits and giggles? I would. It’s fun and hilarious. I knew I laughed my ass off when I read up to that part.
Also, Kotomine ingame did it for a more...not as (much) douchebag reason since he took Kadoc away as a request from Anastasia.