Tau cannon, Michael thinks once cover has been taken and he allows himself the leisure to think. Hmmm... He assumes everyone saw what he was doing earlier, and if they didn't, he'd rather have them scared of him than dead. "Allow me." Without waiting for acknowledgment, he pops up from hiding long enough to shoot off a fireball roughly the size of an RPG explosion, backed by a beam of tau particles*.

* Or possibly fronted by such a beam, given their lifespan.