Dagon

Dagon's power over water and oceanic phenomena. In his evolved form, the technique generates tidal waves, water barriers strong enough to deflect grade 1 attacks, and aquatic shikigami resembling deep-sea creatures. The water itself is cursed, making even contact with it dangerous. As a cursed spirit born from humanity's fear of the ocean, Dagon's technique embodies the helplessness of being caught in open water with things swimming beneath you.

Dagon summons a massive school of fish-like shikigami that attacks from every direction simultaneously. Individually, each fish is weak. Collectively, they're a wall of teeth coming from 360 degrees with no blind spots. The swarm overwhelms through volume. You can't block everything when 'everything' is hundreds of projectiles coming from above, below, and every side. Inside Dagon's domain, the fish gain the guaranteed-hit effect, meaning they don't miss. They track targets with perfect accuracy regardless of speed or evasion. At that point, it stops being a question of 'can you dodge?' and becomes 'how long can you survive getting hit?'

The cruelest visual joke in jujutsu: Dagon's domain looks like paradise. Endless tropical beach, crystal waters, perfect sky. Then the fish start coming. Death Swarm shikigami pour from the water with guaranteed-hit accuracy, and there is no cover on a flat beach. Every fish finds its target regardless of speed or evasion. The beauty is the point. Cursed spirits are born from fear, and there's something deeply unsettling about dying in a place that looks like vacation.