Crimson Sigil

You draw a small sigil on the ground, wall, or object using your blood. When a creature other than you steps within a 5-foot radius of the sigil, it flares crimson and explodes with necrotic energy.

The creature must make a DC16 Dexterity saving throw. On a failed save, it takes 3d8 Piercing damage and is pushed 5 feet away from the sigil. On a successful save, it takes half as much damage and is not pushed.

Once triggered, the sigil disappears.