Clarity

The Clarity Potion is an Item purchasable from the Ancient of Wonders. It's said that a live wisp is captured in each bottle.

Allowing you to quickly get lost Mana back, Heroes can use one to return to the fray or to quickly escape from a dangerous situation. It takes time to restore Mana, so don't use it in the middle of combat. Clarity Potions can also be used on allies, allowing you to quickly pick up a Hero that's low on Mana.

Stacks with itself in inventory.

Regenerate Mana
Restores 100 Mana over the course of 30 seconds. The effect ends if the affected unit takes damage. You can target an ally or yourself to receive the effect. Double clicking the item will use it on yourself.