Lee Tae-gun appears in the foyer of his isolation site, his forced smile melting away with his composure, and he doesn't make it to his bedroom before collapsing.
That dungeon is going to be upgraded to A-rank once he has enough self-possession to write a report. It was one of the hardest dungeons he's done recently, and it was thrilling and exhilarating and dangerous and he had to self-reinforce to the point of nigh-invulnerability multiple times to survive it and he was Lee Tae-gun throughout, this is what he lives for, but now the amount of backlash he's under means it was all he could do to teleport away and get back home before he got rid of all of his clothes in desperation.
His whole body is flushed, his skin tingles, his cock is full mast and he's leaking precum on the floor, his hands are actually shaking and he comes as soon as his hand makes contact with his shaft. That doesn't stop it, though, since a side effect of this backlash is that there's just no such thing as a refractory period for Lee Tae-gun, which is grand, really, except for how it just means he's still a horny mess who can't even go as far as grabbing something, anything to stimulate himself beyond what just his hand can do. No lube, either, so he can't even finger himself, he can just jerk himself off and pinch his nipple and try to drag himself slowly in the direction of something more.