Frog King was left overwhelmed there.
Though he much wanted to leave the realm as champions, didn't he had gotten this far already. Also, didn't he now realized the cruelty of the Nether King? Would he still want to serve such a cruel King?
Definitely, No!
In his heart, he already hated the Nether King and even wanted to kill him for harming an innocent man.
He did not want to serve such an outrageous King.
How could he be so cruel enough to strike Kill Monster with the bewitching sword and used him as a killing weapon?
And to think that if he failed the final tournament he was going to serve that cruel king for the rest of his life, Frog King despised it and wanted to escape far away from this gruesome fate.
Never in his life did he want to serve such a King.
'If possible he too wants to leave the realm along with them.'
And that chance was finally being handed to him on a golden tray.