Benevolence's Black Ice

You create a dark, ice cold ray of death that streaks towards a target. You make a spell attack roll, on a hit you deal 2d8 Necrotic damage and the black ice frezees onto the target, dealing 1d6 Cold Damage as a bonus action on each of your turns for the duration of the spell, until you fall unconscious or die. You can end concentration as a free action.

At higher levels. The damage dealt by the initial beam and the bonus cold damage incease by 1d8 and 1d6 for each level above 2nd.