Encountered a bug here, i am pretty sure this guy was supposed to reward me with a BFG here. Kinda hurts as the later secrets will prove to be quite stingy with giving me this weapon.
The final two levels were my least favourite if i am being honest.
The last one especially as trying to hit a crystal with a rocket like that Icon of Sin fight while being surrounded by constantly spawning high tier enemies and having lost souls preventing you from getting a clear shot is a special kind of bullshit. I might have found a way to beat this fairly if i was willing to waste my time on repeating this segment over and over again, decided that i would rather cheese this by turning on a free mouselook just for this shot.