The Troupe Master is a fiery quest boss in Dirtmouth, gateway to the Nightmare King dream fight and the Ritual ending that consumes him.
The most surprising fact about Grimm is that the Ritual the Knight helps complete kills him. Per the wiki, the Troupe gathers Nightmare Flames to feed the Grimmchild, then "slay the Nightmare King for it to be reborn anew through the Grimmchild." Grimm is not a villain harvesting a kingdom; he is a deity volunteering for his own death so the cycle can repeat.
According to the wiki, Grimm is the master of the Grimm Troupe, a mysterious travelling circus that arrives wherever the Nightmare Lantern has been lit by acolytes. The Troupe and Grimm himself are enslaved to the Nightmare's Heart, the higher being that demands the Flame harvest.
The wiki specifies that Grimm offers the Knight two separate boss fights. Troupe Master Grimm is the theatrical test inside the Dirtmouth tent after two sets of Flames. Nightmare King Grimm is the Dream Nail follow-up after the third set of Flames, fought on his sleeping body and required for the Ritual ending.
This guide covers the Lantern-lighting trigger, the Flame collection loop with Grimmkin enemies, the Troupe Master fight pattern, the harder Nightmare King dream rematch, the Ritual vs Banishment ending choice through Brumm, and the charms most worth slotting before the rematch.
Troupe Master Grimm, leader of the Grimm Troupe and quest boss in Dirtmouth.
Light the Nightmare Lantern in the Howling Cliffs, then return to Dirtmouth.
Troupe Master then Nightmare King, with Flame collection between them.
You picked Banishment with Brumm; the Nightmare King fight is locked out on that file.Grimm is a higher being bound to the Nightmare's Heart. Per the wiki, "Grimm is the master of the Grimm Troupe, a mysterious travelling circus" that "travel from the Nightmare Realm to wherever the Nightmare Lantern has been lit by acolytes." The Troupe gathers Nightmare Flames from ruined lands to "fuel the sinister being enslaving the Troupe, the Nightmare's Heart."
According to the wiki, the Ritual is not optional for Grimm. "Their ritual to feed the Nightmare's Heart consists of feeding first a Grimmchild with Nightmare Flames. They then slay the Nightmare King for it to be reborn anew through the Grimmchild." The Grimmchild the Knight carries is the next-cycle Grimm; killing the current Grimm is how the next one inherits the title.
The wiki notes the Knight's role is "acolyte." Grimm is "aware that the Knight called them with the Lantern and offers them the choice to participate in their Ritual." The Lantern is the in-fiction tether; lighting it summons the Troupe and signs the Knight up as the visiting outsider who carries out the harvest.
The summon chain runs Lantern, tent, child. Per the wiki, Grimm and his Troupe set up tents in Dirtmouth as soon as the Knight has lit the Nightmare Lantern in the Howling Cliffs, the entrance just east of Dirtmouth's well. The lantern is a one-time interact; the Troupe appears the next time the Knight enters the town.
According to the wiki, Grimm reveals himself inside the main tent "in a show of red light and smoke." The first conversation hands over the Grimmchild Charm and sets the harvest task: collect Nightmare Flames gathered by Grimmkin enemies across Hallownest. The Grimmchild must be equipped during the entire Flame run; it consumes each Flame to grow.
The wiki specifies the loop: "With each set of three Flames gathered, Grimm has the Grimmchild consume them to grow." There are three sets, nine Flames total. Grimmkin Novices appear in early areas, Grimmkin Masters appear after the second set, and Grimmkin Nightmares appear after the third. After the second set, the Troupe Master tests the Knight in the tent fight.
The first Grimm fight is a six-attack pattern with a staggered Pufferfish phase. Per the wiki, "Grimm bows to the Knight before the battle. If the Knight hits him while bowing, Grimm screeches at the Knight and counterattacks with the Pufferfish Attack." Skip the bow-strike unless you want to start the run inside the hardest defensive window.
According to the wiki, his moveset is:
The wiki specifies the stagger uses 14 hits at less than a second per hit. When staggered, Grimm "disperses into a swarm of bats" for 3.5 seconds, with the red-eyed bat being him, and a 50-damage cap regardless of hits landed. After the stagger ends, the bats reform.
Per the wiki, Dive Dash counters cleanly with Desolate Dive or Descending Dark timed almost as soon as the dive telegraphs, so Grimm lands in the middle of the spell. In actual play, this is the cleanest damage swing in the fight because the spell hits, his hitbox is still grounded for a follow-up nail combo, and a 2.5x Great Slash lands before he disappears.
The Nightmare King is the dream rematch and the fight that completes the Ritual. Per the wiki, "to start the fight with Nightmare King Grimm, it is required to have the Grimmchild Charm equipped, though the Grimmchild does not appear in the fight." After the third Flame set, Grimm is found sleeping in his quarters and the Dream Nail enters the Nightmare Realm.
According to the wiki, "the base fight with Nightmare King Grimm remains similar, although it is much faster paced, and most attacks gain new properties." The Fire Bats become four bats in a high-low pattern with a gap in the middle, with a teleport-and-two-bat counter when the Knight rushes him. The Dive Dash adds a damaging flame trail. Dash Uppercut spawns six fireballs instead of five and the pause before the leap is shorter.
The wiki specifies one new attack: Flame Pillars. "Nightmare King Grimm summons 4 large pillars of flame. He remains stationary in the air throughout the attack. The pillars are summoned one after another. Each pillar starts forming where the Knight was and reaches the top of the arena." A wide shorter flame stays on the ground for one second after each pillar. The attack ends early if Nightmare King Grimm is staggered, which is the cleanest stagger window in the fight.
The wiki notes the damage scaling: Nightmare King "deals two Masks of damage as opposed to Grimm's one Mask of damage." A run that can soak hits in the Troupe Master fight will die fast against Nightmare King; this is the canonical reason most players take three or more tries on the Dream Nail rematch.
The strongest Grimm loadout pairs Shade Cloak mobility with Spell damage and a healing-window charm. Per the wiki, "the Knight can dash through most of Nightmare King Grimm's attacks if timed properly," which makes Shade Cloak the single highest-impact ability for the fight.
Grimmchild (required for the Nightmare King fight)
Quick Focus (faster heals during Cloak Spikes and Dive Dash windows)
Spell Twister (24 Soul spells, an extra Shriek per cycle)
Mark of Pride (range so Cloak Spikes hits land without contact damage)
Shape of Unn (low-hitbox healing during Fire Bats and Flame Pillars)Per the wiki, "the Shape of Unn Charm is a fantastic way to heal against Grimm. It lowers the Knight's hitbox so the Knight can heal safely during a Fire Bats Attack." In actual play, the Shape of Unn swap is the one-charm change that turns Nightmare King from a damage race into a sustain fight.
The Minion build is a wiki-recommended alternative. According to the wiki, "the Minion build (in full) is Weaversong, Glowing Womb, Grubsong, Sprintmaster, and Defender's Crest (as well as Grimmchild). Weaverlings can damage Nightmare King Grimm during the Pufferfish attack." It trades raw nail damage for free chip while the Knight focuses on dodging.
The Grimm questline has two mutually exclusive endings, locked on the file before the Nightmare King fight. Per the wiki, "if they successfully slay the Nightmare King, the Ritual is completed, and the Troupe leaves Hallownest before the Knight wakes up. The Troupe also disappears if the Knight helps Brumm banish them instead of facing the King."
According to the wiki, the Banishment path goes through Brumm in Distant Village after the Troupe Master fight. Brumm offers to help the Knight banish the Troupe rather than finish the harvest. Accepting walks the Knight to the Nightmare Lantern in the Howling Cliffs where Brumm jabs his staff into the brazier; the Knight breaks the Lantern and the Troupe vanishes.
The wiki specifies the trade. The Ritual ending unlocks the Nightmare King boss fight (and through it the Hidden Dreams DLC dream-boss completion entry) plus the Carefree Melody Charm. The Banishment ending removes Divine from Dirtmouth permanently, locking out any unupgraded Fragile Charm purchases on that save file. Pick based on which loss matters less for the run.
Grimm ties to the Grimm Troupe DLC, the Grimmchild Flame economy, and the Banishment ending branch through Brumm. These spokes cover the connected ground.
Game data and screenshots adapted from hollowknight.fandom.com, used under CC BY-SA 3.0. Original content remains the property of the wiki contributors and Team Cherry.