Asavaels Arcane Reservoir

A magic ring that reclaims a portion of expelled arcane energy for reuse in casting, though it can not hold it indefinitely. 

While attuned to the Reservoir, when you cast a spell of level 1 or higher, roll 1d6 for each level of the cast spell. For each roll of a 6, add one charge to the Reservoir. 

As a Bonus Action, You may expend a number of charges from the Reservoir to regain a single spell slot of a level equal or less than the number of charge expended.

All charges are lost on a long rest

Notes: Wizard, Druid or Sorcerer, Combat, Jewelry