Whirlwind Cleave

Your immense physical training has granted you the ability to strike with such overwhelming force that it unleashes a projectile of pure slicing wind.

When using a melee weapon with which you are proficient, you may choose to forgo any additional attacks to instead deliver a single, devastating strike. Make a standard weapon attack. Any creature hit by a 30-foot long and 5-foot wide line, originating from you, takes slashing damage equal to 1d10 plus your strength modifier.

Creatures in melee range take both the slashing wind damage, as well as the initial damage of your weapon attack.
Characters sacrificing two or more extra attacks may deal an additional 1d10 slashing damage.