Nexomon

This achievement pops after capturing or evolving one of each Nexomon in the database.
Almost all of the normal nexomon can be found in the wild and the legendaries can only be found once you have completed the post game story.
A few tips that i noted on my playthrough:
-Every new area has a set of nexomon that can spawn there and will always have 2-3 rares, 1 mega rare and 1 special nexomon in it. You can try to find them all on your first visit (which is great for levelling and what i did) or you can wait until you have completed the Phantom Citadel as you get a charm there that increases your chances of finding a rare or higher nexomon.
(There is a great guide on steam already linked below that lists each screen and every nexomon that can spawn there).

https://steamcommunity.com/sharedfiles/filedetails/?id=19313...

-Commons do not evolve at all, Uncommons evolve once, Rares, Mega Rares and Specials evolve twice. Legendaries do not evolve.
-When you get to later areas you will find the evolved forms of the nexomon families so if grinding and evolving isn't for you, you can simply catch them later on. (You get so much money and items that this is easily done).
- If you want to evolve nexomon to fill the database then it may be worth catching the basic forms and waiting until the Frozen Tundra to go on an evolving spree as you get an item there that shares the full exp value across the whole team.
-All of the legendaries are roamers (apart from the titans that you need to go through a sidequest to obtain) and can be found anywhere on the map with grass/encounters once you have completed the post game story and created the radar. The easiest way to find them (albeit the most boring) is the hop between two screens with grass on and wait for the "Legendary Nearby" prompt to pop up. Please be aware that the Legendary you find will be random and you may find one you've found before.
-As for the Titans, you will need to track down and defeat each of the 65 warden "clones?" and the titans will appear in your storage like magic. The warden battles all have between 3 and 6 nexomon varying from level 83 to 99 so it will be worth grinding a little before taking these guys on. My levels at the end of the game were 151-153 so its not hard, just time consuming.
-The easiest place to level is the Netherworld as you get more exp there and getting my Nexomon to level 99 there took around 2 hours or so.
Thats all i can think of for now but I'll edit if i think of anything else :)