Withering Sigil

Level 3 Necromancy (Sorcerer, Warlock, Wizard)
  Casting Time: 1 Action
Range: 60 feet
Components: V, S, M (a shard of blackened bone or glass, which the spell consumes)
Duration: Concentration, up to 1 minute

  You sketch a crooked, star-warped sigil in the air. It brands itself onto a creature’s shadow, rotting muscle and reflex alike. The target must make a Constitution saving throw. On a failure, the target takes 4d8 Necrotic damage and becomes cursed by the sigil. While cursed in this way it suffers the following effects:

• At the start of each of its turns its takes 2d6 Necrotic damage.
• It has the Poisoned condition.
• Its Speed is reduced by 10 feet while it does not have the Bloodied condition.
• While it has the Bloodied condition it also has the Slowed condition.
• It has Disadvantage on Strength Saving Throws.
• It has Disadvantage on Dexterity Saving Throws.

At the end of each of its turns, the target can repeat the Constitution saving throw, ending the effect on itself on a success.
  On an initial success, the target takes half as much initial necrotic damage and is not Cursed, but its Speed is reduced by 10 feet until the start of your next turn.
  Using Higher-Level Spell Slot. The initial and ongoing damage increases by 1d8 and 1d6, respectively, for each spell slot level above 3.