"Roar!!!"
In the next second that person late out and angry roared toward the king and instantly began to go towards him to attack him.
At this time just looking at that person you can naturally tell he already became a monster, not only just a monster but he became a mindless monster that only knows how to attack. Most likely because of this he also decided to attack the king at that time. But the thing was that even though using the artifact that person became that much powerful but he still did not reach the same power level as the king so in the end King just defeated that person with just one attack.
Most likely those other Traitors wanted to use the same thing but before they could use anything, all of them became unconscious. Naturally the king did all of this and made everyone of those Traitors unconscious. Actually he increased the pressure and because of that those people were unable to breathe and became like that.