Retch Rust

You exhale tendrils formed from flakes of rusted metal. All creatures in a 30-foot area take (scaling+4)d10[slashing|options:area-damage] damage with a fortitude save against your class DC. A metal creature that fails its save also takes (scaling+2)d4[persistent,slashing] damage.

Level (+2) The cloud's slashing damage increases by 1d10 and the persistent damage increases by 1d4.