Magic can be twisted and changed when exposed to enough evil.  Fallen Priests often fuel this process

A creature of your choice that you can see within range takes damage equal to 1d4 + your spellcasting ability modifier. This spell has no effect on undead or constructs.

At Higher Levels. When you cast this spell using a spell slot of 2nd level or higher, the damage increases by 1d4 for each slot level above 1st.