Trace

When struck by a ranged melee attack or spell you can use your reaction to create a line of coloured magic energy which traces its way back to the one who launched the attack.
The target takes 1d10 radiant damage, and they start to glow in the same colour as the line. The glow fades after 1 turn and any attempt at stealth for that turn is at disadvantage.

You can cast this spell at higher levels. For each level of spell the glow persists for an additional turn. ie (a third level spell would have the glow remain for 4 turns)