Blight Bud

You fire a barrage of seeds at a target you can see within range. On hit, the seeds deal 3d6 piercing damage and the target makes a Constitution save (spell save DC). On a failed save the seeds embed themselves in the target's body. If the target uses any magical ability (spells, racial traits, etc.), then it takes 2d8 piercing damage. For every consecutive use of magic by the target, the damage taken increases by 1d8. On it's turn the target can take an action to remove the sprouts from its body but take 3d6 piercing damage.

Only the initial attack requires a concentration check from the target (if it is concentrating on a spell).

At Higher Levels. When you cast this spell using a spell slot of 5th level or higher, the initial damage increases by 1d6 for each slot level above 4th.