Baelfyr

Some Spellcasters can reach into the depths of their soul, to pull out the very force of their power. An Etherial fire ignites (the player chooses the color) on a target they can see within the range of 60ft. On a hit, the target takes 3d10 Psychic damage. 

If the target is undead or Infernal in nature the target takes 3d12 Radiant damage. If an undead target is reduced to less than half its hit points it is Instantly destroyed. 

At Higher Levels. When you cast this spell using a spell slot of 2nd level or higher, the damage increases by 1d10 (1d12) for each slot level above 1st.