He's playing Dark Souls.
They mentioned the 'Four Kings' boss fight, which, as far as I am aware, has been beaten without weapons and without armour, but is essentially impossible without both at the same time, even if you can use items, so the run in this chapter is quite insane even without the girlfriend demanding him not to use items on top of that, and him beating it first try without batting an eye to the point that his girlfriend finds it boring basically means that he got gud.