Blade Arms

You raise your arm (or arms) and make a slashing movement with them. You drop on the ground what you were holding and your arms transform in to blade-like appendages. Now you can use them as swords. You can use your arms to make weapon attacks. You are proficient with this new weapon, and it has the Finesse property. You can add your Spell casting ability modifier to both the attack roll and the damage roll. The damage die is 1d8 and the type is Slashing .If you transformed both of your arms, you can use your bonus action as well to attack with it, like with dual-wielding. The spell ends after one minute or you can use a bonus action to end it.