Kid vs Kat
Kat to the Future, Pt. 1 / Kat to the Future, Pt. 2
S2 E8:
Coop uses Kat's time machine to go back and stop Millie from ever finding Kat but ends up altering the future for the worse. Coop tries to undo the Kat invasion, which he brought about by fooling with Kat's time machine.