Death Spike - Blood Empowerment

Using Blood Empowerment, you can up cast this cantrip to a spell. It becomes a 3d8 and increases by an additional 3d8 ray per spell level. This costs 1d6 + your constitution modifier for each spell level. 

You create a single ray of powerful necrotic energy and hurl it at a target within range. 

Make a ranged spell attack for each ray. On a hit, the target takes 3d8 + your spellcasting ability modifier necrotic damage.

At higher levels.  When you cast this spell using a spell slot of 2nd level or higher, you create one additional ray for each slot level above 1st.