By temporarily reaching level 102, Minos had reached a level of power that would allow him to easily have total dominance over an opponent of up to level 107.
However, as much as that undead was at level 108, Minos' powers were special within his Space and Time Domain.
If that creature hadn't been so close to Minos, if it hadn't been unprepared, it would have been able to move even a little within the space under Emperor Stuart's influence. But by confidently grabbing Minos' neck with its hands as it prepared to defeat its opponent, this creature made the big mistake of underestimating him.
As the Flashdrain sacrificed itself to prevent the death of its host, Minos' power skyrocketed, just as he had predicted would happen in this battle.
Knowing what would happen at this point in the battle, Minos was not slow. When he felt his cultivation at such a new level, he caused space and time around him to stop functioning properly.