See Spin Attack Only One Command Overview
This custom command adds a spin attack to your character in your Minecraft world. Hold down shift to charge your forces. Once you hear a short sound, release the shift-button to unleash a Spin Attack, which kills all mobs nearby immediately (doesn’t work for players, Wither Bosses and Ender Dragons). After you used this power you need to rest a while, before you can charge your forces again.