Biggest of Bonks

you point your finger at an ally's hand, upon doing so, they gain the following benefits

• their next melee attack will add 2d20 damage to their damage type of choosing (must be one they can use)
• their next attack roll will have advantage
• their attack roll doubles, a critical hit will make their damage roll have advantage, and your regain the spell slot

the spell's damage is multiplied by the spell level