Breath of the Scaless Wyrm

You combine your arcane essence the rod in your hand imbuing you with the power to spew the pale, accursed breath of Seath the Scaleless. Wile you maintain concentration on this spell you may use your bonus action to exhale a shining white mist in a 60 foot cone, generating a rough spiked crystalline surface over the surface of the area it covered, any creature in this cone must make a constitution save or take 9d6 force damage, half on a successful save. on a failure the targets movement speed is reduced by 10 foot, any creatures speed who is reduced to zero in this way becomes petrified until such a time as a remove curse spell can be cast on them. Each time you use your bonus action to breath this mist you create another crystalline area, these patches of cursed crystals do not disperse until they are dispelled even after the spell ends.