Power Word Stun

Hit Points Duration
50 or less 4d4 rounds
51–100 2d4 rounds
101–150 1d4 rounds

Enchantment (Compulsion) [Mind-affecting]

Core Rulebook
Level: Sorcerer/wizard 8, witch 8
Casting Time: 1 standard action
Components: V
Range: Close (25 ft. + 5 ft./2 levels)
Target: One creature with 150 hp or less
Duration: See text
Saving Throw: None
Spell Resistance: Yes

You utter a single word of power that instantly causes one creature of your choice to become stunned, whether the creature can hear the word or not. The duration of the spell depends on the target's current hit point total. Any creature that currently has 151 or more hit points is unaffected by power word stun.

Mythic

Treat the target's current hit point total as though it were lowered by 5 times your tier. For example, a 3rd-tier archmage casting this spell would affect a creature with 60 hp as though it had 45 hp, and the spell would last an additional 2d4 rounds. You can target a creature with more hit points than this spell could normally affect, causing it to become dazed for 1 round.

Augmented (6th)

If you expend three uses of mythic power, the magic of the word lingers around the target. Until the beginning of your next turn, if the target's hit points are reduced enough to put it in a lower category for the spell's effects, the spell affects the creature according to its new hit point total. For example, a creature in the 101–150 hp category reduced to 80 hp is immediately stunned for an additional 1d4 rounds. The spell's effects don't diminish if the target regains hit points.