You shouldn’t have a problem unlocking the commons, but when it comes to acquiring Rare, Epic, Legendary, Mega, or Guardian Minos, you’ll want to check this brand-new (and relatively quick) Mino Monsters 2: Evolution strategy guide.
One of the easier ways to find non-common Minos is to go to the islands. But we’re talking easy in a relative sense, as you’ll have to lure them with better candies than the common one you usually bring with you. The best thing to do is to sap out their health until they’re close to dying before you draw them in with the candy. These monsters are easier to catch if they’re on their last gasp and therefore unable to put up much of a fight.
We’ve got a separate strategy guide that covers evolution in depth, but for purposes of this one, you can also evolve Minos to improve their rarity by a notch. Non-Guardians, however, cannot be evolved to Guardians, but any other Mino can be evolved one tier higher. Be sure to level them up (first to Level 25, then to level 50), and once there, hunt for the specific berries they need for evolution.
Monster chests, which can be bought in the store, can guarantee you a chance at a rare Mino or better, but mostly a rare one and nothing more. You’ll have to pay 50 gems for one chest, and gems are this game’s premium currency. You can also try the Dragon Chest, which isn’t exclusively populated by Minos. However, if you’re able to catch a Mino but not a guardian stone, that Mino will be elevated to the highest non-Guardian rank.
Some of this game’s rarest Minos can only be bought at the in-app store, so that’s something you really will have to deal with. Interestingly, Crystal Island is an in-app “item,” but going there allows you to catch a rare Mino called Zyphyrmane.
Go to the Guardian area in the game and you’ll be able to view the types of Guardian stones in order to unlock the Guardian Mino. Simply tap on the picture of the stones, and take note of where you have to go to get them. Most of the time, these are events, which are harder than most other modes but completely worth considering what’s in it for you.