Years ago I had a GM who would tend to do that - he'd just roll damage and tell you what your character got hit by. Considering this was Champions, and there were rules for reacting to attacks (dive for cover, abort to dodge) I felt this was frustrating.
I had a campaign where the PCs were trapped in the Aztec underworld, and I wanted them to have a guide. Because of some myth I read, I gave them a small black dog with a nametag that said "Virgil". All Virgil ever did was run around fights doing Aid Another actions, but the players loved having...
Reef Dwarves. They discovered that there were jewels in the ocean, so they went after them. Problem - dwarves are terrible swimmers. But they can hold their breath a long time. So they walk out to the oyster beds and back.
I wrote up something like that a while back, for a pair of dragonborn PCs - I primarily remember that dragons considered Avarice to be a virtue, sort of the opposite of Sloth. Like how some humans consider Ambition to be a virtue while others don't.
I feel like the problem with the spell is that the 100 hp threshhold is too low for modern D&D.
What about something simple like "This spell automatically kills one creature - A legendary creature may expend a legendary saving throw to negate the effect?"
I always wanted to base a campaign world around surrealist landscapes, but I haven't found very many pictures to use that didn't include blatant references to technology, so I haven't gone further with the idea.