"I WAS TOO CONFIDENT!"
At the last moment before dying, this was the last thought of the Basking Shark. A thought of indignancy filled with regret, double regret, and regret again.
As an old purple tier predator who was the only one of his species in this whole region, he could be said to be a veteran who already survived countless near-death experiences and was already daily life to him.
As a veteran, he almost never acted rashly, preferring to evaluate risks before engaging. He also evaluated this group of Great White Sharks before engaging. At first, they didn't seem like threatening opponents at all.
And this assumption was what caused his death.
After the first clash with Sebastian, the mere fact that he couldn't kill a lesser-tier shark brought him huge humiliation. This was more prominent when this shark had the sound domain too, it was like a tight slap across his face.