first you need to complete the main story line, get every Pokemon on youre rescue team, & get lucario rank. then restart and you shud be jarachi or celibi.
it depends what partner you want and what Pokemon you count as rare.
I have Pokemon dungeon explores of darkness but if I were you, I would battle legendary Pokemon twice to get them in your team.
In Pokemon Mystery Dungeon: Explorers of Darkness, the Golden Apple is a rare item you can find in Treasure Hunts. It is also an item you can find in the Golden Chamber which is a rare area to find in dungeons.
look the best you can
It's very rare to start with a cuebone in Pokemon mystery dungeon blue, but I once started with a cuebone and oh how he was strong! It's rare, but able (I forgot how to start with cuebone), you just need luck, and chose only boy! I now have an eevee and i got her in the start by chosing the last possible answer for the questions and picked "girl", and I was a eevee! I chose as partner, charamander! Hope helped, Lucario's secret aura!
Mt. Travail 1F - 19F Very Rare
That would depend on how good you trained your Pokemon but if you wanted the best rare Pokemon, that would possibly be Mew.
sometimes in dungeons you will find a door if you have a key you can open it the door sometimes the door opens to a rare Pokemon that can be recruited or a rare item
solve missions and you will get further and unlock new dungeons i know i completed it
you can recuirt lucario at jourys tover 90-99 its really rare
After you defeat the elite 4 as well as the champion Gary the only new area that opens up is the mystery dungeon in Cerulean city. In this dungeon, you can find rare and high level pokemon.
Well, since they r mystery dungions, u can find them any where but note: they r extremly rare!