ULTRAKILL: New Tablet & Future Secret

The boss is located in the level 4-3, once in the level play normal until the room with the four pillars. After exiting the room with the four pillars you have to light, look to the left. You will notice the walls have art of the enemy Filth on it, the 4th one will be cracked. Shoot it out with the shotgun.

Once you shoot out the wall, enter and you will turn into a hallway. To your right will be a fire pit you can light to open the door and loop back around to the checkpoint. To the left will be a blocked off door, shoot the door with the shotgun.

When you enter the room title “Tomb of kings” look to the right and shoot out the 1st coffin, and grab the blue skull.

Place the skull on the pedestal, this will awaken the Druid Knight. He’s a pretty easy fight, here’s a tip if you parry the shotgun right as he does the fuller auto attack. It will parry his projectiles right back at him, doing a ton of damage to him. Once you beat him you will notice that the tomb the Knight came out of is now glowing.

Take a look inside and you will see the newly added tablet, and it will say:
This is referring too a secret in the next level 4-4. Beat the level and go into 4-4, or quit out if you’re a ♥♥♥♥♥.

Now that you’re in 4-4, go up to the part with three doorways.
Go to the door on the right and use the whiplash arm you get after beating 4-4 to grab the blue skull.
When you grab the skull the door will open, pull out the railcannon (make sure it’s the normal version) and shoot at the water to open the next door. This will show you a message telling you that they will be something added soon. How soon? I don’t know, as soon as Hakita is done making the secret just give him sometime.