Enemies Encountered: Flea Rider.

Upon entering the Upper Castle Keep, you will find yourself in a dark room with a central platform. Standing on this platform will slowly illuminate the room and raise you to the top.

From the top, jump right, then through the ceiling gap, and into the room on the right to find the Falchion sword.

Return and go to the room on the right to enter a save room.

Leave the save room and proceed to the door on the left with the red carpet on the platform.

You will see a destroyed staircase; you need to reach the top of this area by gravity jumping or using the bat form and entering the room on the right.

In this room, you will find Life Max Up and Heart Max Up items on four platforms. At the bottom right, the Ghost card relic is located, granting you the Ghost familiar. This familiar latches onto enemies and drains their life.

Leave this room, transform into a bat, and fly left. Transform back into Alucard when you hit the left wall.

Once you land on the red carpet, you are in the Prologue area. A switch is located behind the top part of the entryway threshold. Jump to attack the entryway's top part to reveal the switch. Hit it again to reveal a ladder from the ceiling.

In the room at the top, you will find several breakable pots containing: Frankfurter, pot roast, turkey, Sirloin, resist stone, resist dark, resist holy, and platinum mail.

Return from this room, avoiding the door on the left for now.

To explore the remaining gray area in the Castle Keep, you must first deal with the Flea Riders. Use gravity jumps to lure them, then attack them as you fall.

After eliminating a good number of Flea Riders, you can use your bat form to fly to a pocket just below the top of the keep. Here you will find the Power of Mist relic, which extends the use of your Mist form, and Fire mail.

You are now finished with the Castle Keep for the time being, except for three rooms at the very top which will be addressed later.

Your next objective is to go to the Royal Chapel on the far left of the Castle. Drop down from where the Flea Riders were, exit to the right, drop down again, and proceed down the long hallway through the red doors to reach the Royal Chapel.