Though he didn't use his Water Transmutation skill in the previous battle, the fact that the jellyfish was about to last so long against the 3 of them told Sebastian all that he needed to know about the strength of the jellyfish.
Individually, his team could trash it as easily as crushing a bug but when it came to hundreds of them swimming across, escaping was the only choice. Sebastian had no second thoughts about his decision.
"Swim!" "Swim!"
Tosh and Shanks did not dare to tarry for one second longer, they both turned and swam as fast as their tails could carry them.
[You have activated skill: Triple Reverse Swim.]
As Sebastian escaped, he felt the need to activate his advanced dash skill to go even faster but seeing the pitiful Shanks, he could only sigh in resignation.
Though he was escaping, this did not make him ignore this anomaly.