In Pokémon Mystery Dungeon: Explorer of Darkness, you can recruit Legendary Pokémon such as Articuno at the peak of Mt. Avalanche however it requires a special Wonder Mail code, Zapdos can be found in Amp Plains however it needs a Mystery Part or Secret Slab item, Mewtwo can be found in the Dark Crater and Deep Aegis Cave but it requires the Mystery Part/Secret Slab iem, Mew can only be found in the Deep Mystery Jungle with a Wonder Mail code, Raikou can be found in the Concealed Ruins and Entei can be found in the Deep Dark Crater however you will need the Mystery Part for both Raikou and Entei, Lugia can be found in the Surrounded Sea and Ho-Oh can be found in the Mt. Mistral and they can be found as long as you have the Mystery Part item in your posession and Celebi can also be found in the Mystifying Forest however you will need the Mystery Part item and it can only be found in Pokémon Mystery Dungeon: Explorer of Time.
Same with any other legendary, you get as many tries as you want.
Yes
Nope
you can not recruit mew but you can recruit mewtwo cya later
You have to complete the game, and then recruit it.
You can recruit legendaries and do more things.
You can recruit legendaries and do more things.
You cant start as a shuppet but you can recruit it somwere
Nope.only in the final maze
evolve all of your pokemon,recruit all the legendary pokemon.
2
in the second cave