The Nest of Evil's environment greatly resembles both a coliseum and a black market fighting arena. This hidden (and optional) area acts much as other challenge runs found in other Castlevania titles in which the player heads through a series of rooms and do battle with increasingly tougher groups of monsters.
How to unlock
To gain access to the Nest of Evil, there are a number of requirements the player must first satisfy:
- Complete 13th Street - After completing 13th Street, Wind will make the "The Nest of Evil" quest available if talked to at the Entrance.
- Have at least one free "quest slot" - The player is only allowed to be working on five quests maximum at a given time. If there are no free "quest slots" available, even if they've already completed 13th Street, the quest won't be able to be selected. The player must then complete any other currently accepted quests to free a slot. However, if there are any other quests stacked in queue before "The Nest of Evil", the player must keep completing them until it finally becomes available.
- Have at least 888% map exploration rate - Having a 100% map exploration rate in every painting found in the castle still won't be enough to open the entrance to the Nest of Evil. What the player must do is to concentrate in exploring most areas within Dracula's Castle (Entrance, Buried Chamber, Great Stairway, Tower of Death and Master's Keep). In a normal playthrough it is most likely that the area comprised between the Entrance and the Nation of Fools will still remain unexplored when the quest is first available, so that's a good place to start. If that's still not enough, then the player should check all of the maps in the menu and look for those stages which still have big areas unexplored.
- Find the entrance - The quest only states that "the path to the "Nest of Evil" will open at the castle gates". This should be a hint to know where to look for the entrance to this area. If the player checks their map, they will notice a new small gap appearing on the floor of one of the rooms at the Entrance. This passageway can be found below the castle's drawbridge (in the same room where the Change and Call Cubes were found at the beginning of the game).
There are 64 rooms in all. Each division of this area consists of a floor with three challenge arenas before a vertical "breather" hall on the left side of the map that leads to the floor below, with two challenge arenas and a boss arena immediately following. After the boss arena there is another vertical passage, this time on the right side and with a Warp Point in the middle, which precedes the next set of challenges, then the cycle repeats itself.
The Warp Points are all located on the right hand side of the map. There are also two Save Points in this area, one stationed at the beginning and one near the end, just before the Doppelganger's arena.
- Main article: Nest of Evil/Challenges
The most devastating Dual Crush in the game, Greatest Five, is located inside the final room following the defeat of the Doppelganger. Additionally, most of the lair masters may drop rare or exclusive items when defeated.
- Main article: Nest of Evil/Enemy Data
- A level in the 2004 Game Boy Advance game Shaman King: Master of Spirits, also by Konami, has a similar design to the Nest of Evil, with the latter most likely being a reused asset rather than a nod to that game. In addition, many enemies and the overall structure of some levels in that game seem to be inspired by the Castlevania series.