Comet Azur

hold your arcane focus forward and open a portal into the very primeval current itself, sending forth a hurling beam of volatile cosmic energy and eviscerating anything within its path.

deals 60d4 force damage to every enemy, half as much on a successful dexterity save, in a 15 foot wide and 150 foot long beam, anyone caught within the beam is knocked prone for 2 turns and if a spellcaster is hit with this they become silenced for 4 turns.