Bloodheart Stake. The impaler is magically bound to the ceremonial stake and the sacrificed corpse the ritual caster used to create it. If the impaler is reduced to 0 hit points, it disappears, then re-forms 1d8 hours later in the nearest unoccupied space to the stake and regains all its hit points. The impaler dies only if it is reduced to 0 hit points while either the ceremonial stake is removed from the sacrifice's corpse or the impaler is on a different plane of existence from that corpse.

Legendary Resistance (3/Day). If the impaler fails a saving throw, it can choose to succeed instead.

Multiattack. The impaler makes one Spike attack and two Wicked Spear attacks.

Spike. Melee Weapon Attack: +11 to hit, reach 5 ft., one target. Hit:15 (2d8 + 6) piercing damage, and the target's speed is halved until the start of the impaler's next turn.

Wicked Spear. Melee or Ranged Weapon Attack: +11 to hit, reach 10 ft. or range 20/40 ft., one target. Hit:13 (2d6 + 6) piercing damage plus 13 (3d8) necrotic damage.

Spike Burst (Recharge 5–6). Twisted, spectral spikes shoot out from the impaler's body. Each creature within 30 feet of the impaler must make a DC 19 Dexterity saving throw, taking 40 (9d8) force damage on a failed save or half as much damage on a successful one.

Speed Spike. The impaler teleports up to 30 feet to an unoccupied space it can see. It can then make a Spike attack.

Deepen Wounds (Costs 2 Actions). Each creature whose speed is currently reduced by the impaler's Spike attack takes 18 (4d8) necrotic damage.