acid rain

A green and black cloud forms above the targets and acid starts raining from it. The targets in an area of a cylinder with radius 15ft must make a constitution saving throw. If they fail they take the full 4d6 poison damage or half of it on a succesfull throw. They are all be considered poisoned and will need to make a DC 15 constitution saving throw each round for 3 turns. On a failled throw they will take 2d6 poison damage and on a succesfull one 1d6.

When you cast this spell using a spell slot of 5th level or higher, the damage (both initial and later) increases by 2d4 for each slot level above 4th.