In the expansion The Binding of Isaac: Repentance has included many new features, including new floors to unlock in which you will find new enemies and final bosses and it will also help you to see new endings. In the following guide we will explain all the steps to enter Corpse .
How to unlock the Corpse floor to fight Mother
To access Corpse you have to follow a series of very specific steps. It is mandatory to fulfill each and every one of them because otherwise it will be necessary to start the game from the beginning to be able to access this new floor, which in turn is one of the last levels , such as Chest or Dark Room.
To start you have to defeat the final boss of Basement, Burning Basement or Cellar, be it the one on the first or second floor. This will bring up a door that can only be accessed if you have a key that will lead you to a room with a manhole cover, which in turn will take you to the depths of Downpour or Dross.
In either case, you will have to go to the second floor of this place until you find a white fire in one of the rooms. As soon as you touch it, your character will leave his body and will transform into The Lost , so you have to be very careful, because in a single hit he will die, unless you have unlocked the Holy Mantle object so that it can withstand one hit per room.
After transforming into The Lost you will have to look for a room with a mirror, which will take you to an alternative version of the floor with the rooms placed in reverse. You will simply have to find the object room, where you will find the handle of a knife, also called Knife Piece 1 . Then you will have to go back the way you came and return to the normal version of the floor.
When you beat the final boss, a door will appear that you can blow to pieces if you carry a couple of bombs , the amount necessary to destroy it. In this way you will come across the entrance to Mines or Ashpit, where once again you will have to go down to its second floor and look for three yellow buttons that will be scattered throughout the area. As you pass over all of them, you will hear a melody and a noise to make it clear that something has been activated.
So, you should look for a vertically elongated room with a wagon in which you can get on. From there you will go to a place where at first you will lose all the power-ups and objects that you have caught and where you will see no enemy. After going through several rooms you will get the knife blade, that is, the Knife Piece 2 object , but at that moment the atmosphere will change completely and Mother’s Shadow will appear, who will chase you to kill you.
You will have to do all the way back, this time avoiding a few obstacles and traps in which you will have to use bombs or press switches, break locks using keys, etc. So until you return to the original floor, at which point you will recover all the power-ups, objects and statistics that you had.
When you beat the final boss of Mines II or Ashpit II, a new door will appear that will only open at the cost of losing two whole hearts . Be very careful because if you don’t have enough life it will kill you when you try to open it. On the contrary, if you succeed, you will descend to Mausoleum or Gehenna and from there you will have to go down to the second floor to face a harder and more difficult version of Mom who will shoot rays from the walls or step on the ground more frequently.
If you defeat it, you will see a closed red door that will open if you throw the knife that you have previously collected. There a different version of Mom’s Heart will be waiting for you that will make practically the same attacks as the original version, although it will launch more shots than normal that will be more difficult to dodge. All you have to do is get out of this encounter to return to the previous room where a hole will have emerged that will finally lead you to Corpse.
From here, you will only have to advance normally until you reach the second floor of Corpse, where the final battle against Mother , one of the game’s most powerful bosses, will await you, so bring enough hearts and a good collection of power-ups, because you will need them if you want to defeat her.
