Flamestrike
Legend
They float useless mid-air while the party deals with the rest of enemies. After that we have fun pelting it to death. Since most encounters often get done by round 5 or 6, that gives the whole party 5-4 rounds to focus down the target before the spell ends.
It has a duration of 10 minutes, not 10 rounds doesn't it?
Had a PC caster drop this on an Ogre once.
He felt pretty good about himself until the Ogre pelted his club at him (improvised weapon), hitting him and forcing a Con save to maintain concentration.
I dont see it much because many critters in 5E come with ranged attacks, breath weapons, spells or whatnot. So it's reasonably situational, and few casters have the slots to spare on it (other than Wizards).