What is Grigorius the Grigori??

[Edi]

Originally Posted by Gregstrom

Units turning into Grigorius is probably a bug rather than WAD.

He is a real in-game unit, although you'll only ever see him by Wishing for a Grigori.

Yes, it's a bug. A very rare bug that nobody has managed to make consistently reproducible. Before there was a Grigorius the Grigori, there was Old Centurion, a legacy unit from Dom1 that has not been used even in Dom2. So to prevent wishing for the Hinnomite Grigori, Grigorius was added. Before that particular patch, some units sometimes turned into Old Centurions and vanished.

Though if there is some sort of flavor text, it might even be the warped sense of humor Illwinter has sometimes demonstrated. But I doubt it.