Done!
Now that the rewards are set, Mu You felt motivated.
He didn't need to go to the fifth level just yet.
Mu You controlled his avatar to return to the fourth level, delivered the promised KFC to Little Fatty, and handed him an item for safekeeping - the Second Fragment of the City of Dawn.
He found no better place to store map fragments than this Underwater Prison!
If others wanted to get this fragment, they'd have to infiltrate the fourth level, help Little Fatty escape, and snatch the fragment from him. As the territory of the Octopus King, the world's hardest jail to escape from, doing so would be nearly impossible. Otherwise, legendary pirates like Dragon Knight Finn wouldn't have been left helpless.
Also, specifically leaving a '2' on the fragment would cause some confusion for the remaining two forces.
After taking care of all this, Mu You returned to the second level and continued hunting Scarecrows for an attack boost.