Everyone was taking note of what Oscar was up to for one reason or another. For instance, they wanted to know what he had become. Clearly, his head was detached from his body, and somehow he was still moving and alive. Even his strength was different from before.
At the same time, they had all felt Agent Three's strength for a brief moment, and they could tell he was strong. This was why they were regularly paying attention to the fight, and they had seen that Oscar had dominated Agent Three throughout the whole fight.
Oscar had strength before, his soul weapon was unique, and he was one of the best users of his earth ability. Still, without his demon tier weapon, many wondered whether he could or should still be considered one of the strongest along with the big four.
Which was why the military needed more strong figures other than just Oscar. However, after seeing what he had just done, without a doubt, he was now deserving to be called one of the strongest.