Aqua Axe

This Spell is a Rare Spell these type of spell you need to find or unlock from a spell scroll or some other Source(optional rule)

Your hand (or another appendage) is engulfed in water held in place by a magical field in the shape of an axehead. When this spell is in effect your unarmed strikes deal 2d8 +spellcasting modifier, slashing damage. This water is nonmagical and is affected by extreme heat, spells or magical effects that destroy water.

At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the axehead becomes larger Increasing range to 10 feet. For each spell slot level above 3 add +1d4 to the slashing damage. When you cast this spell using a spell slot of 7 or higher, the water is replaced with lava and deals an extra 1d12 fire damage and the slashing damage is changed to fire damage, fire immunity is treated as resistance when this deals fire damage.