Of course there's no autohit in Hero*, but the usual way is with some combination of One Hex AOE, +OCV, autofire, sometimes NND does body, and sometimes even attack vs. ECV. Much like Sleep it becomes outrageously expensive, even after you tack on Charges 1x/day, but that just goes to show you how OP Magic Missile really is. Especially compared to Magic Mouth. Or Tenser's Floating Disc. The only reason it's not radically unbalanced in D&D is because of the hit point system there.
* Which is a feature, not a bug.