Try to complete the game as much as possible (must have beaten rayquaza. You must have the friend bow and be lvl 100 and quite a lot of IQ (If possible, all IQ) Then after several attempts he'll recruit, I got rayquaza 1st time! Save at the half way point so If you dont recruit then turn power off and try again :)
You can recruit Aerodactyl in Sky Tower :D
I believe if you look at red rescue team it is the same.
To recruit Groudon in Pokemon Mystery Dungeon Red Rescue Team, all you need to do is go to Magma Cavern , go to the final floor, (there are just under 30 floors) and battle Groudon. To increase recruitment rates, have your rescue team leader holding a friend bow, have a high rescue rank and level. **Make sure that the rescue team leader (you) hits the final hit on the Pokemon that you are trying to recruit, and m make sure that you have enough space on your rescue team for groudon to join.** You can only have up to 6 stars of space on your rescue team, so 2 starter Pokemon or one larger one, you can check its size under 'summary.' Egrentii
Wish Cave 99F
recruit the legendary birds
You can't recruit Pokemon in Tiny woods
Actually I don't think you can recruit any Pokemon really easy
Yes you can
you cant
It is free when you battle and recruit him.
you get it autonatically when you recruit Ho-Oh
purity forest