Vergesh's Volley of Quills

You throw a quill into the air and choose a point within range. Hundreds of duplicates in every colour stream in a volley of colourful beams of light from above and then dissappear.

Each creature in a 15ft radius, 40ft high cylinder centered on that point must make a Dexterity saving throw. A creature takes 10d8 damage on a failed save, or half of that on a successful one. The damage type is piercing.

In addition, one chosen Ability Stat, Creature Type, AC value, Resistance or Immunity from one creature whom failed their Dexterity save is gleamed by the caster.