Nightmare King Grimm
Complete walkthrough with step-by-step instructions, tips, and strategies.
Nightmare King Grimm (NKG) is widely considered the hardest boss in Hollow Knight. He's fast — faster than anything you've faced. Every attack has a tight dodge window, and mistakes cost 2 masks of health with the right build.
The fight is a rhythm game. Once you learn the tells and dodge patterns, it becomes a dance. But learning that dance takes patience.
Recommended Charm Build
| Charm | Cost | Why |
|---|---|---|
| Shape of Unn | 2 | Heal while moving — essential for the short healing windows |
| Quick Focus | 3 | Faster healing — turns .5s windows into viable heals |
| Unbreakable Strength | 3 | 50% nail damage boost — ends the fight faster |
| Mark of Pride | 3 | Extended nail range — safer pokes |
Total: 11 notches. If you have fewer, prioritize Shape of Unn + Quick Focus + Strength. The survivability is more important than extra damage.
All Attacks & Counters
Attack 1: The Dive
| Tell | Action |
|---|---|
| NKG disappears in a puff of bats | He'll dive from above — dash forward or backward to avoid the dive hitbox |
After the dive, he leaves 4 fire trails on the ground. Jump over the first, dash through the second — you'll be in perfect position to hit him. This is your primary damage window.
Attack 2: The Fire Pillars
| Tell | Action |
|---|---|
| NKG bows and fire erupts from the ground beneath you | Walk slowly left or right — the pillars spawn at your current position, so moving gradually spaces them out |
Four pillars spawn in sequence. Walk, don't run. After the fourth pillar, NKG is vulnerable for one nail hit.
Attack 3: The Stab
| Tell | Action |
|---|---|
| NKG points forward and his cloak stretches | Shade Cloak dash through him immediately — he stabs forward with a massive reach |
After dashing through, turn around and hit him once. He'll teleport away. This is one of the safest damage windows.
Attack 4: The Bats
| Tell | Action |
|---|---|
| NKG sweeps his arm and 4 bats fly at you in an arc | Jump over the first bat, shade cloak through the second — the bats spread wider as they travel |
After the bats pass, NKG is vulnerable. Hit him with an Abyss Shriek (descending dark) for massive damage if you have soul.
Attack 5: The Spikes
| Tell | Action |
|---|---|
| NKG slams the ground and spikes erupt diagonally | Stand between two spike rows — the gaps are safe spots. Don't jump unless you have to |
Spikes have a fixed pattern. Memorize the safe spots. No damage window after this attack — focus on survival.
Attack 6: The Flame Orbs (Phase 2 only)
| Tell | Action |
|---|---|
| NKG fires 4 fireballs in a spread pattern | Dodge between the gaps — the pattern is fixed; move to the safe zone after the first shot |
Phase Strategy
Phase 1 (100% - 60% HP)
NKG cycles through Dive, Stab, Bats, and Spikes. Focus on survival and learning the tells. Don't try to damage-race — you'll get hit. Accept that your only hits come from the counter windows after each attack. 1-2 hits per cycle is good.
Phase 2 (60% - 30% HP)
NKG adds the Fire Pillars attack. The arena floor starts crumbling — some sections disappear. This changes your movement options. Stay in the center area, which remains safe longest.
Phase 3 (30% - 0% HP)
The Flame Orbs attack is added. NKG fires tracked fireballs. More floor disappears. Heal windows shrink to almost zero. This is where Shape of Unn + Quick Focus pays off — you can heal during the dive attack's fire trail phase.
Attack Quick Reference
| Attack | Tell | Dodge | Punish |
|---|---|---|---|
| Dive | Bat puff | Dash → jump over fire | 2 nail hits |
| Fire Pillars | Bow | Walk slowly | 1 nail hit |
| Stab | Cloak stretch | Shade Cloak through | 1 nail hit |
| Bats | Arm sweep | Jump → dash | Abyss Shriek |
| Spikes | Ground slam | Stand in gap | None |
| Flame Orbs | Spread fire | Dodge gap | None (survive) |