Before coming here, the Old Beast Monarch took great care to instruct him that no matter what, he must maintain the correct attitude. The Endless Beast Sea had already shown signs of decline and couldn't compete with the flourishing Immortal Powers. Therefore, it could not afford any more turmoil.
In fact, even without the Old Beast Monarch's reminder, the old man would have done the same.
The individual in question was a Supreme being, a unique existence in the entire ancient times, capable of easily suppressing him with just a thought. Even if he had ten thousand guts, he wouldn't dare to act recklessly in front of such a life-like existence!
To be honest, it was utterly unexpected for him that there would be a creature daring to speak impertinently in front of such a presence, even threatening the Supreme. To the old man, this was akin to tempting fate.