Blister

Choose a creature that you can see within range. You cause the creature to boil and blister under its skin, if the creature has no skin it begins to corrode. The creature takes 5d8 Necrotic damage when you cast the spell. Until the spell ends, you can use a bonus action on each subsequent turn to cause this damage again.

If a creature is killed by Blister then all creatures within a 5ft radius take 2d10 acid damage on a failed dex save, if succeeded then the damage is halved. This happens due to the creature who was killed, exploding from the inside out

At Higher Levels. When you cast this spell using a spell slot of 6rd level or higher, the damage increases by 1d8 for each slot level above 2nd.