R key tainted cain

[Bergman777]

Can you craft this item or what? can't seem to find it, i have the item description mod so can see all crafts available on my floor but never even seen it :(

[GMsU | Rebikas]

Yes, it is very possible. The issue is likely you not finding the correct pickups/materials.
Materials needed is randomized by the run seed but usually you need 2-3 bone hearts and any number of golden pickups but bone hearts are the most important because R Key is part of the secret room item pool and bone hearts are the corresponding pickup for that item pool in the same way that eternal hearts are for the angel room item pool.

[JellyPuff]

You'd typically want to look for a few Bone Hearts coupled with high-quality pickups, like golden one's (Golden Bomb, Golden Pill, etc).