Players be like
It seems to me that the insects from Insect Plague are a magical effect and not creatures that can be defeated or altered.
Furthermore, even if they were actual locusts as per the spell, they would be unwilling to turn into elephants and plummet to their deaths.
So. There is an insect swarm 200’ above the BBEG’s head and the druid is trying to cast an 8th level spell with no legitimate targets.
Paladin, you’re up.
I mean the spell says it conjures locusts. I don’t see any reason to think otherwise.
The second bit is more interesting since locusts almost certainly aren’t capable of understanding or consenting to a spell effect and don’t know they would die if they participated. But I would rule all creatures that can’t understand enough to consent automatically reject such magic.
There’s nothing in the verbiage that lets you fight off the insects in any way. Fireball it? There’s still locusts everywhere. Didn’t even thin out the cloud.
Maybe if a summoned swarm of insects had mass charm or mass suggestion cast on it to cause the insects to obey, I’d allow that although it clearly bends the rules even at that point.
Animal Shapes, as another pointed out, has a range of 30 ft, so either the elephants can’t fall as far or more shenanigans need to be added. (Distant Spell, if it can be obtained, still only makes that 60 ft.)
