Dream Destroyer Grimm

Dream Destroyer Grimm is a boss added as part of the Eternal Palace update. He is a purified variant of Grimm, who has mastered the power of Dreams and has become one with the Nightmare's Heart.

Lore
Following the death of the Nightmare King and the continuation of the Ritual, Dream Destroyer Grimm is the leftover power of the previous Troupe Master. He lingers the kingdom, searching for another entry to the Nightmare Realm so he can reunite himself with the Nightmare's Heart once more. After finding the Nightmare's Heart, he is turned into essence and sucked into the Heart itself. The Heart reforms itself, using Grimm as it’s host, and becoming the Dream Destroyer Grimm. Only one thought remains within it’s mind: revenge.

Location
To fight Dream Destroyer Grimm, Nightmare King Grimm needs to have been defeated previously. If the Troupe was banished, Dream Destroyer Grimm cannot be fought.

First, the player needs to Dream Nail the original Grimm Troupe bug corpse in the Howling Cliffs. Grimmchild needs to be equipped for this to work. Afterwards, a tent is set up in one of four locations:


 * Inside the Beast's Den, replacing the trapped bench.
 * Near the top of Watcher's Spire, where the Watcher Knights were originally fought.
 * On the Palace Grounds, on the opposite side of where the White Palace entrance is.
 * In the Resting Grounds, where the Dream Shield charm was originally acquired.

Behavior and Attacks
Dream Destroyer Grimm is an extremely hard, endgame boss that should be faced with caution. He is a Dream boss, which means losing to him will not count as a real death. He has various attacks that all deal two masks of damage, and combining that with his extreme speed and large health pool, Dream Destroyer Grimm is truly a formidable foe.
 * Fire Bats: The bats launched by Grimm move much quicker than the bats in the NKG fight, and Dream Destroyer Grimm does not stay in one place during this attack. The bats take a patterned route consisting of both high and low flying bats. As soon as the first bat is launched, Grimm immediately teleports to the other side of the arena to launch the second bat. Then he teleports once more to his original side to launch another bat, and back to the other side to launch the final bat. He is too quick to be hit during this attack, unless you launch a perfectly-timed Shade Soul at him.
 * Cloak Spikes: Similar to NKG’s Cloak Spike attack, Grimm does not appear during this attack. Spikes now shoot from the walls as well, in an alternating pattern between both of the walls that forms a grid alongside the original set of spikes on the ground.
 * Dive Dash: Grimm’s and his flame trail now covers the entire arena, and is much faster.
 * Dive Dash Uppercut: This is a combination of the Dive Dash and the Dash Uppercut from NKG’s fight. Grimm starts at a random point in the room and dives down, like in the Dive Dash attack. However, after his horizontal dash is finish, he uppercuts up, sending out 8 fireballs, as well as an arc of fire that covers 50% of the arena.
 * Flame Pillar: Grimm will shoot out three flame pillars: one pillar shoots out in the middle of the arena, dividing the arena in half. The two other pillars disconnect from the first pillar and follow the Knight with no cooldown in between the flames launching up. Grimm can teleport around the arena while this attack is  used.
 * Pufferfish: Grimm’s fireballs have been replaced with dark spikes that now follow the Knight. The spikes can only turn up to 30 degrees and will move forwards in a straight pattern afterwards. At 50% health, this attack is accompanied by a ring of fire that surrounds Grimm and expands outwards. A ring is sent out every three seconds, and can only be dodged via Shadow Dashing.

Other Appearances
This Grimm variant also appears in S3E10 of the Vessel of Blood television series as a foe of Blood Wasp.