Diamond Dust

Intense study and practice has allowed for you to cast spell to cocoon your enemies with a giant icicle like sculptor originating from the ground. This spell takes one round to fully gather the power and upon the 2nd round, it will incase targets within a 5 ft radius of your choosing. Upon a fail or save, the target is encased within the icicle and is unable to take dmg from anything but the spell itself.  You then cause the ice to explode, anyone within 10 feet of the icicle takes 4d12 cold damage unless successful con save and the terrain within 10ft of the original point becomes frozen.