Need help with the Phobia level Blood

Does anyone know how to beat this level on Myst? I'm guessing the intended strategy is to get the Arch-Viles to kill the Cyberdemon, but they always end up dying, and I only have 50 bullets to finish it off, which is never enough.

I haven't played it, but unless this map[set] changes some basic Doom2 behavior, archvile attacks don't hurt cyberdemons in the first place, so that's obviously not the solution.

Lüt said:

but unless this map[set] changes some basic Doom2 behavior, archvile attacks don't hurt cyberdemons in the first place

Wrong.

That said, I haven't played the wad either.