it comes with the Pokemon
No. It is a friend area in Pokemon Mystery Dungeon Blue/Red Rescue Team.
Moltres' Friend Area is Legendary Island. You get Legendary Island upon recruiting Moltres, Zapdos, or Articuno.
That would be Legendary Island. You get it when you recrit Articuno, Zapdos, or moltres.
If you mean in Mystery Dungeon no. Zapdos's Friend area is Legendary Island which you get Auotmaticly after it joins your team
There is no dungeon called final island, if you mean western cave then the answer would be mewtwo
To get legendary island go to articuno,zapdos or moltres and recruit either one of them. you can recruit them one by one. just walk in circles in the battle field at least 3 times. You can recruit other legendary Pokemon by doing the same thing. Once you recruit zapdos ,articuno or moltres you will automaticly get the friend area legendary island.
99 floors
there are 20 floors.
Go to Legendary Island and have Moltres Articuno and Zapdos recruted. Then you get access to Silver Trench which is 99f and on the hundreth floor you get to battle Lugia
Blizzard Island You have to defeat Froslass in Blizzard Island to rescue him.
You will gain access to the Silver Trench which contains Lugia on the 99th floor if you have recruited all three legendary birds and talk to Alakazam and then go to the Legendary Island friend area.
In the Zero Island West B40F