@Am0or
So when the MC came to the tower, he felt a immense amount of malice radiating in his direction. As per his usual tactic with his "Instant Death" skill, he promptly snuffed out the source of that malice. This was the Devil trapped in the middle of the barrier. But since the barrier is made of extremely compressed time, it's near impossible to have known that the Devil was dead as a result of this. He also killed multiple other people in the tower, who were also extremely powerful and likely were summoned by fate to ensure the Devil wouldn't escape, which would have been extremely dire if the Devil wasn't dead already.
The "Goddess" that has been assisting the super-unlucky guy just revealed that his entire existence was meant to make something horrific happen to kill the super unlucky guy, as she's actually aligned with the Devil. Except, once again, all of it was rendered null and void by the MC instantly ending the Devil.
In short, the MC literally killed a whole bunch of people who were supposed to solve a problem, while also solving the problem at the same time. So everything that all these people did, was made pointless by him just being there.