Rain Jirachi, Scarf Kyogre, Phys. Def Ho-Oh, Lugia, Dark / Psychic Arceus --> Mewtwo
Which Thundurus? In any case just revenge kill it or Dragon Tail it out with Giratina-a.
Good stall should have a good general scarfer or a catch-all phazer (or at least the stuff the rest of the team can't handle).