Sword Shift

With a wave of your hand, you transform whatever weapon you're holding into an entirely different sword. The blade has the light and finesse property, and you are considered proficient with it. Upon hitting an enemy with the weapon, it suffers 3d8 slashing damage. You can also use your reaction to imbue the blade with a spell that has been cast by a combatant in the encounter. It will deal 2d10 of that type of damage (i.e: If Fireball is cast, you can choose to imbue the blade with 2d10 of Fire damage with your reaction) and the spell cast has be targeted at you or an ally within 5 feet of you. The blade stays active until the duration ends, you drop the blade, or use your bonus action to dispel the blade. When any of these events get triggered, the blade reverts back to its normal form.

When casting this spell at any level above 5th, the d8 and d10 count both increase by 1. (Example: If you're casting using a 6th level slot, you gain an extra 1d8 and 1d10.)