If you want to obtain all of the pokemon, make sure to catch Misdreavus in the trap pokeballs which are found in naljo ruins, because is the only place where you can get him/her. Get and hatch the gold egg and silver egg (ask google/youtube for their location)
What is to do for 'Legendary Hatchlings'? With the Itemfinder, it didn't take me long to find it. It is located in the Tunod waterway (Had to comb the place twice to find it) I had this exact problem with the last gold token and also had to ask for its location. The route 48-B token is near the place that appears in the image IIRC, but I don't remember the exact spot. Here it is the location of each gold token. The official site says 'Added an extra Gold Token in Phacelia City' but impossible to find it with the Itemfinder.
If Bingo 3 can not be completed, the last Gold Token I miss is 'Overworld Token # 65'. Hardest cheevo in the set, never could have done it without your help Thanks! It's possible to bring 2 underleveled (lvl 40 minimum?) with your lvl 100 pokemon so that the opponents won't be high level for a good number of rounds. I have a team of Phancero, Kyogre and Varaneous, all of them with 40000+ EV, but between sturdy and enemy crits, you need a lot of luck. With that, the only one that worries me is the 20 wins in a row in battle arcade.