Deltarune Chapter 3 Guide – How to Get the Shadow Crystal
So, I finally beat Chapter 3 of Deltarune — and wow, getting the Shadow Crystal was a wild ride. If you’re wondering how to actually win that “impossible” Roaring Knight fight, you’re in the right place. The secret? You need to grab the Shadow Mantle first — and that means diving deep into hidden content most players totally miss. Let me walk you through exactly how I did it.
🌨️ Step 1: Getting the Ice Key
Everything starts with earning S-Rank on Board 1. Trust me, it's not easy, but you need that S-Rank to unlock a hidden door in the Green Room.
- Get S-Rank on Board 1.
- That unlocks the S-Rank Door in the Green Room. Go through it and use the big computer inside.
- Play the alternate version of Board 1 through that computer. Beat it, and you'll get the Ice Key.
Next up: Board 2.
- Continue the main story to Board 2.
- Again, aim for S-Rank.
- Now with both S-Ranks and the Ice Key in hand, you're set to unlock the real meat of the challenge.
❄️ Step 2: Using the Ice Key
Back in the Green Room, go through the S-Rank door again and enter the Bonus Round changing room.
- Head to the starting area of the alternate map.
- Enter the left cave and grab the Sword.
- Use it to fight enemies and fish until you hit Level 2.
- Once you're Level 2, go to the raft room, destroy the weeds, and ride up the waterfall to reach the ocean area.
- In the top-left corner, land at the ice-covered barrier.
- Use the Ice Key to open the Ice Door.
Things get real spooky from here — the environments change completely.
🧊 Step 3: The Ice Dungeon & Shelter Key
Inside the Ice Door is a dungeon. Grind enemies here to reach MAX Level.
- Once you’re maxed out, you can smash the orange barriers.
- You’ll meet an NPC in a White Cloak.
- Exit the screen and they'll start following you — now they shoot ice magic when you attack.
Now comes a puzzle section:
- Freeze enemies, turn them into ice blocks, and use them to hit switches.
- Then you’ll enter a looping maze.
- Watch the White Cloak — if you go the wrong way, they’ll stop moving.
- If they keep following, you’re on the right path.
Solve the maze to reach a mysterious door. Open it to earn the Shelter Key. You're making progress!
📺 Step 4: Getting the Shadow Mantle
Later in the story, you’ll revisit the Green Room while escaping Mr. Tenna.
- Use the Shelter Key to enter the TV in the S-Rank Room.
- Go right in this new city area to find a Sword — but there are no enemies.
- You’ll have to attack your own party members (yep, Susie and Ralsei) to level up.
Once leveled:
- Break the guard rails on the right to reach a tough dungeon.
- Clear each room to grind more levels. There's a spot with weak monsters that drop healing candy — save that for later.
- Once you're strong enough, bust through the orange barrier and fight Mr. Tenna again.
- After the fight, head into the Shelter.
💀 The Boss Fight
- Inside the Shelter is a tough boss — I’m talking multi-phase madness.
- Phase 2 starts throwing minions at you. Defeat them quickly to get more healing candy.
- Save as much health as you can for the final phase — it’s brutal.
Beat the boss, and you’ll switch control to the real Kris. Head right, open the chest, and boom — Shadow Mantle acquired.
🛡️ Step 5: Beating the Roaring Knight & Getting the Shadow Crystal
Okay, now for the final stretch.
- After the Tenna fight in the main story, you’ll face the Roaring Knight.
- Normally, this fight is unwinnable — the attacks are just insane.
- But with the Shadow Mantle equipped, things change. You take way less damage and can survive long enough to win.
The goal isn’t to completely defeat the Roaring Knight — just last long enough and deal enough damage to “defeat” him temporarily.
Once you do that?
💎 You’ll finally get the Shadow Crystal.
Final Thoughts
Honestly, this might be one of the hardest hidden quests in any Deltarune chapter so far. It took me hours to figure it all out and even more time to master the fights. But the payoff is worth it — the lore, the boss fights, and the gear are all top-tier.
Good luck out there, and may the Shadow Mantle protect you!