Arcane Leech

Your dealings with the arcane have allowed you to gather up the threads of magic you unravel.

When you successfully cast Dispel Magic or Counterspell, roll a d20 - on a roll of 19 or higher, you restore a spell slot equal to half the level of the Dispelled or Countered spell (rounding down). For example, if you Dispel a spell of 5th level, you could choose to regain a 2nd level spell slot.

If you have no expended spell slots after Dispelling or Countering a spell, nothing happens.