@Nk9bjP4A
No, the MC doesn't say anything about the guildmaster, he only says that he came via an emergency portal and any records of his presence on the floor have been erased. This only strengthens his position as the prince has no one at the guild to lean on, and makes the prince himself reporting anything even more difficult.
As I mentioned before, he cannot afford to fun afoul of the guild or he's screwed. He could potentially kill the prince and his knight as they are unrelated, but if he kills any adventurers, even if the guildmaster says she won't speak about the events, to assume that he has a blank pass is absurd. Even if we do assume that he can, guild-wise, kill all he wants, we first have to assume that he CAN reasonably kill any/all adventurers he encounters. If he fails to kill any single one, then again, he's screwed. Considering that he's already been clearly shown as weaker than the average adventurer previously, and the extent of his current possession boost is completely unknown, it's also unreasonable to assume that it somehow makes him suddenly unstoppable against higher tier adventurers.
Yes, I agree that this is less satisfying as a plot development, however it's honestly much more consistent with the the story we've seen so far. He is a weak underdog in a world where actual hero's and gods walk, he has to walk delicately at all times and he knows it. It's far better to make the prince himself not want to mess with him again through fear and confusion than to push his luck in an unfamiliar location surrounded by unknowns. Remember, he already has what he came for, he only real objective is getting the elf out in one piece again.