Ellinill's Blessing

Being blessed by the pools spirit and completeing the ritual, you have become enlightened by the God of the Underworld.
You have forged a new pact with Ellinill himself, bound in blood., whilst your pact is not enough to become a Warlock, you do learn one Eldritch Invocation option of your choice from the warlock class list.
Your spellcasting ability for the invocation is Intelligence, Wisdom, or Charisma (choose when you select this feat). If the invocation has a prerequisite of any kind, you can choose that invocation only if you’re a creature who meets the prerequisite.