This is an experiment with Enter the Gungeon where I spawn Glitched Chests in floors where you are unable to find them in the normal game.
This is also known as breaking the game.

The reason I didn't show me opening Glitched Chests in the Oubliette or Abbey is because opening one in the Oubliette takes you to the Gungeon Proper, and the Abbey takes you to the Mines. Which is a tad boring.
Opening a Glitched Chest in the Past will take you to Bullet Hell.
I'm using EtGMod to do this.