Path of the Lich: Arcane Restoration (Intelligence) (UA)

You gain the following benefits.

Ability Score Increase. Increase your Intelligence, Wisdom, or Charisma score by 1, to a maximum of 20.

Essence Rejuvenation. When you use Soul Siphon to consume a soul, you can choose one or more expended spell slots to recover. The spell slots can have a combined level equal to no more than 4. Once you use this feature, you can't use it again until you finish a Short or Long Rest.