Eldritch Champion

Studying occult lore, you gain one cantrip from the Warlock spell list and you learn one Eldritch Invocation option of your choice from the warlock class. Your spellcasting ability for the invocation is Intelligence, Wisdom, or Charisma. Whenever you gain a level, you can replace the invocation with another one from the warlock class.

Once per turn when you hit a creature with an attack, you can expend a charge to deal extra force damage to the target, and you can knock the target prone if it is Huge or smaller. You deal a number of d8s equal to your current highest spell slot level to a max of 5d8. You have 2 charges per long rest.