Dorvarex's Thunderbolts

You conjure three bolts of crystallized lightning. Make a spell attack roll against a creature within range for each crystal. Each crystal does 1d4 lightning damage on hit and become stuck into the creature it hit. Additionally, you may hold concentration on this spell; on each of your turns after casting this spell you can use your bonus action to cause 1d4 lightning damage per crystal stuck to a creature. A creature can remove all the crystals stuck in it as an action, and if you drop concentration the crystals fizzle into nothingness.

At Higher Levels. When you cast this spell using a spell slot of 2nd level or higher, the spell creates one more crystal for each slot level above 1st.