Instructions
Enter Archon's Knot, a dungeon located next to the Cullis Gate at Brightwood Tower.
Swim through the entrance area until you arrive at the stars. Climb up into the hallway above and keep moving forward until you encounter a closed door.
Use a ranged weapon like a bow or rifle to fire at the glowing orb floating above the door to open the door. Walk through it to the next area.
Climb the stairs to access a room covered in spikes. Employ a ranged weapon to fire at the orb floating beside the left wall, and then scurry across the floors before the spikes return until you encounter a closed door with an orb in front of it. Use a ranged weapon on the orb to open the door. Travel to the next area.
Follow the path until you encounter a room with spokes and a blue switch. Step on the switch and go back down the stairs you came up from until you encounter a new passageway that wasn't there before. Walk through it.
Approach the green statue, use the Bloodlust Roar skill on it, and then return to the room above with spikes in it. Employ a ranged weapon on the newly appeared orb, and then run across the floor before the spikes reappear. Use a weapon on the orb at the end of the corridor, and then follow it as it moves from that position to the left side of the room, where there's a door. Travel through the door and climb the stairs.
Enter the room at the top of the stairs and turn right. Approach the treasure chest and open it to get the legendary katana, Daichi.