Richter Warping Glitch
To activate this glitch, you have to be playing as Richter, and must be in the Inverted Castle Keep. Once you reach the Inverted Castle, advance to the left, until you reach the broken staircase. Using Richter's uppercut move (down, up + jump), jump up through the broken staircase. At the top, where the statues are, there will be a door to the left. Advance through the door. There will be two elevator platforms in the room. When you reach the top, take the door to the right. While going through the hallway, there will be risen platforms on the floor, and tombstones to fight through. When you reach the last risen platform on the floor, stand to the right of it, and push up. This will warp you back to the normal castle.