How to storm Dracula’s Castle
While it’s not exactly difficult to start the Return to Castlevania DLC in Dead Cells, it’s not as simple as selecting it from a menu. For that matter, it’s not even available immediately upon starting a new game of Dead Cells. There are certain criteria to getting into it, though they can be met pretty quickly.
The basic idea is that you need to find Richter in the Prisoner’s Quarters biome (the area you start in). However, he’s not exactly standing beside the welcome mat, nor is he immediately available. He first appears when the flasks show up near the starting area. This happens after you’ve restarted three times. You can either wait until this happens naturally or just force it. If you’re starting out for the first time, getting a feel for things isn’t a bad idea.
Richter will then appear within the biome. You’ll know you’re headed in the right direction when you see stairs. The entrance to the Castle Outskirts is not always in the same place, so you may need to search the biome a bit.
Returning to Return to Castlevania
After you’ve completed the Castle Outskirts, you’ll move on to Dracula’s Castle. Finishing that stage will put you in a fight with Death. Afterward, you’re spat back out to the regular levels. Once you make it back to the Prisoner’s Quarters, you’ll meet up with Alucard, who will tell you that in order to make it to Dracula’s throne, you’ll need to enter Dracula’s Castle through the Clock Tower stage.
To get to the Clock Tower stage, I’d recommend checking out a biome world map, as there are a few ways to get there. However, my preferred route is:
Promenade of the Condemned->Ramparts->Black Bridge->Slumbering Sanctuary->Clock Tower.
You’ll have to actually complete the Clock Tower biome, move onto the Clock Room, and beat the boss there. Alucard will then intercept you and guide you back into Dracula’s Castle. While this permutation of Dracula’s Castle may look the same, there’s a Medusa boss fight lurking within, and completing the biome will move you onto the final battle with Dracula.
Note that you can’t enter the Castlevania DLC twice in one run. If you enter the Castle Outskirts, you can’t later re-enter Dracula’s Castle through the clock tower. Alucard will straight up tell you that it’s not possible and shuffle you off to the next level. It’s one or the other.