Saber Puzzle

The Ancient Relic being held by a player

You will now have the Ancient Relic in your item slot. Go back to the Jungle and prepare for the final battle. Find the stone building where Blox Fruits Gacha is located. Beside the stairs, you will see a relic-shaped hole in the wall. Just equip your ancient relic received from the Rich Man and plug it in, a door will open and Saber Expert will be inside (If he is not inside, someone probably killed him already. Wait for a few minutes. He respawns every 30 minutes. If this does not work after a little bit, try server-hopping via the built-in "Servers" button.).

He is Level 200 and is quite a hard boss if you are Level 200. A strategy to fight him is by staying outside of the room which he spawns him because he cannot exit the room, and attacking him through the invisible barrier which he cannot pass through. However, be sure to pause every few attacks to avoid the red slashes. You can also use ranged attacks at the same time. You will need to deal at least 10% damage and after you kill him, he will drop a Legendary sword, Saber, and you will unlock the ability to buy Instinct from Instinct Teacher for 750,000 if you are Level 300 or higher.

You need to be at least level 200 to fight him or else you will get a message saying "The entrance rejects you. You're not ready yet." Don't worry if you die with the Relic in your inventory, as you can keep getting the Relic from the Rich Man, even if you leave the server.