#pathologic cathedral

I started with Google image search. This was the closest result (haut-relief of apostle Mark on the gate of the temple of Christ the Savior in Moscow):

The guy looks similar but that's not him.

Then I googled the gates. Turned out that the temple has multiple gates, all with haut-reliefs.

These are the eastern gates. Looks familiar, right?

Yes, this is the main door of the Cathedral.

Then I found an article with a bunch of photos. Here's our guy:

According to the article, it is Matthew the Apostle.

But what about other textures?

A photo of another gates was used for the interior. Moreover, the relief for the arch was taken from there.

An edited version of a carpet page from the Book of Kells was used for the steps to the throne.

A street lamp next to the temple was used to texture the window bars.

There are also reliefs from the façade on the street lamps.