[quote=@Fish of Oblivion]
[quote=@The Silver Paladin]The Moon Cell grail summoned Buddha. Your argument is invalid.
[/quote]

The Moon Cell is also a completely different Grail from the Fuyuki Grail, with different (read: basically nonexistent) restrictions on who can be summoned. It's not a good measuring stick for this, especially considering that goddamn Arcueid of all people got summoned by it, whilst apparently still alive at that.
[/quote]

True. The Moon Cell has been around even longer than the Holy Grail, and it also created its own reality just so the real world wouldn't get fucked up. So yeah. I agree with Fish.

Edit: and the protagonist from Fate/Extra had an NPC of him, despite him being still alive, because the Moon Cell didn't know that he was still alive because he was in Cryo stasis.