What do you do with the two key pieces?

[khani]

In the spike room where you give hearts you get the two key pieces but what does the key do exactly? I got them on room 1 or 2 and made it all the way to the end and it did nothing? I thought it would unlock some sort of boss or item but it didn't do anything.
Can somebody who has devoted their life to this game help me.

[Tato]

Defeat the boss of The Chest or The Dark Room once, then the key becomes useful.
There's a different way to get those key pieces by the way, but it's only available after the above criteria is met.

[Rip Van Winkle]

the key pieces is been used for defeting the boss in the chest or dark room SPOILER---------- its is mega satan

[khani]

Originally posted by LitQuid:

Defeat the boss of The Chest or The Dark Room once, then the key becomes useful.
There's a different way to get those key pieces by the way, but it's only available after the above criteria is met.

Alright thanks!

[Tato]

Originally posted by Amliam:

the key pieces is been used for defeting the boss in the chest or dark room SPOILER---------- its is mega satan

You can mark spoilers using the ["spoiler"] and ["/spoiler"] tags (no "), like this:
I'm hidden!

[Danizk0]

Originally posted by LitQuid:

Originally posted by Amliam:

the key pieces is been used for defeting the boss in the chest or dark room SPOILER---------- its is mega satan

You can mark spoilers using the ["spoiler"] and ["/spoiler"] tags (no "), like this:
I'm hidden!

You can use [noparse] and [/noparse] to avoid confusion, like this:
You can mark spoilers using the [spoiler] and [/spoiler] tags

[Tato]

Originally posted by Danizk0:

Originally posted by LitQuid:

You can mark spoilers using the ["spoiler"] and ["/spoiler"] tags (no "), like this:
I'm hidden!

You can use [noparse] and [/noparse] to avoid confusion, like this:
You can mark spoilers using the [spoiler] and [/spoiler] tags

TIL, thanks!