There is no dungeon called final island, if you mean western cave then the answer would be mewtwo
After beating the game it becomes available for purchase at Wigglytuff's shop
After you beat the Final Maze, Marowak gives you a Brown Bow, which raises Attack, Defense, Sp. Attack, and Sp. Defense by 1, and won't be lost on a failed mission. Just like the bow you get at the start.
No there isn't but there are wonder mails codes to get one friend area at a time or you can use the max money code and just buy them all.(p.s. Some are only avalible after you beat Rayquaza.
I am Pretty sure Mewtwo Because he is genetically made to be the ultimate Pokemon
at final island
not sure maybe mew?
After beating the game it becomes available for purchase at Wigglytuff's shop
Someone
Me! Lawlawlowkozl
48 floors
It's the Darkrai battle, as also seen in Pokemon Mystery Dungeon Explorers of Time/Darkness.
no
48 flloors
48 floors
after you beat the final boss
it depends it could range from 10 to 50 or even 100
There are 50 floors.