Arcane Reflection

 You reflect the triggering spell back at it's caster.

If the triggering spell was Level 5 or lower, it is reflected, turning the caster into the target. If the spell requires an attack roll, you make the spell attack with Advantage. If the spell requires a saving throw, the target makes the save against their own Spell Save DC.

If the spell is Level 6+, you must make a Constitution saving throw against the target's spell save DC. On a success, the spell is reflected, turning the caster into the target. On a failure, you are affected by the spell.

Using a Higher-Level Spell Slot. The threshold for the spell being automatically reflected increases to match the level of spell slot one below the slot used for this spell.