Sacrificial Altar

[Pastapockets]

Everyone else I know got this the moment they booted up the new patch, but I didn't.

What the heck am I missing? How do I unlock it? Nobody seems to know... My game was already 100%'d so it must have been some obscure task I'd never managed to do across my thousands of playthroughs. But I've tried all sorts of things like killing myself to devil beggars/devil room deals/sacrifice rooms and whatnot. What else could possibly unlock it?

[°¬°]

i got it at one point after receiving the mark from a devil deal

[Pastapockets]

Holy zombie thread batman