Secret #84? what is it? how i get it?

[MiniDemon]

Hello,
I played the binding of isaac a lot and I got almost every Achievement except #84.
I looked at many sits but no one could help me.

I'm thankful for every help.
p.s. sorry for my bad english, not my main language

[Whitelink]

It's the Real Platinum God.
You need to do everything with the Lost on Hard, and touch the items unlocked.

[MiniDemon]

Ok thank you :D
but i already did everything with the lost in hard mode.
and i found every item, there is no question mark left
except for one big question mark behind my found items on the last page

thats it: http://steamcommunity.com/sharedfiles/filedetails/?id=442466677

[MiniDemon]

ok, thank you frost and you too whitelink :)

[Jabelonske]

The big question mark is actually a visual glitch, it is supposed to be a question mark the size of the other items shown. But anyways, as people already told you, it's the icon for the godhead you're missing.