Existential Perturbation

You target a humanoid and afflict it with questions of existence that weigh heavily on its mind. Its speed is halved and it has disadvantage on all attack rolls. It may make an Intelligence Saving Throw at the end of each of its turns. The first time it fails, it takes 2d8 psychic damage. If it succeeds, it avoids damage for that turn. A creature needs three successes to end the effect.

Each subsequent failure after the first, it takes twice as many dice of psychic damage as it took from from the previous damage instance. (If a creature fails three times before shaking the spell, it takes 2d8 + 4d8 + 8d8 = 14d8 total over multiple turns).

If a creature is killed due to damage dealt by this spell, its head explodes.