Tal'Vo's Chaos Blade

You run your hand along the weapon used in the spell’s casting and imbue it with an undulating, warbling mass of chaotic energy. the energy is imbued for 1 hour and requires your concentration then the chaotic energy dissipates. The weapon has a +2 bonus to attack rolls on a hit, the target suffers the weapon attack’s normal effects, and you cause the target to take an additional 2d8 damage. If the weapon isn’t already a magic weapon, it becomes one for the duration. choose one of the d8s rolled to determine the attack’s damage type, as shown below.