Callum's Elemental Backlash

You point your finger, and the creature that damaged you is momentarily surrounded by elemental energy. You choose Acid, Cold, Fire, Lightning, Poison, or Thunder, the creature must make a Dexterity saving throw. It takes 2d8 damage of the chosen type as well as the associated effect on a failed save, or half as much damage and no effect on a successful one. Below are the associated effects of each of the damage types:

• Acid-The creature is covered in acid and takes 1d8 acid damage at the start of its turn. A creature can use an action to remove the acid from itself or another creature.
• Cold-The creature is covered in ice which reduces its speed by half until the end of its next turn.
• Fire-The creature is blinded until the end of its next turn.
• Lightning-The creature is stunned until the end of its next turn.
• Poison-The creature becomes poisoned at the end of each of the poisoned target's turns, the target must make a Constitution saving throw. If the target succeeds, it is no longer poisoned
• Thunder-The creature is deafened until the end of its next turn.

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