You Have Completedd The Game Give Up
he's in western cave
There are loads in western cave.
Mystery dungeon blue:- At the end of western cave. 99f western cave. Must have friend area.
Western Cave
There are several deungeons you can get it. You can get him in wish cave and western cave.
after u beat deoxys in meteor cave 20th floor.
in a key door on western cave B59F
Recruit Ho-oh from Mt. Faraway. Then, an event will trigger, opening Western Cave.
Yes, there is alot! such as, Western Cave Purity Forest Deep Sea Cave Silver Trench and many more!!!
In the western cave or most likely in fiery field.
When you recruit Lugia in Silver Trench, the next dungeon will be Meteor Cave, which is the place you can recruit Deoxys.
There is no dungeon called final island, if you mean western cave then the answer would be mewtwo