Quad

Increases damage by several times. At about 4. Lasts 30 seconds.
Found in secrets, starting from the basement.
== At the mini boss ==
On the left side of his room, where there is a "window". If you throw a teleport right in front of you, you will fall into a secret room where there will be a quad, it will help kill the Nightmare (4 hits are enough to kill the Nightmare)