The gacha in this is prob the most ill conceived basura in a mobage, and ive played my fair share. It goes:
RNG for the type of characters you can get. (Wanted a specific colored type of unit and didn't get that colored circle on the summon screen? Too bad, you're out 5 orbs).
RNG for the character you're gonna get.
RNG for the RANK of the character you get (WHY? /Getting/ a character you want is hard enough as it is!)
RNG for the stats of the character you get. People claim that the average out once you get to level 40, but you can still get massively screwed over the course of leveling if the game just wants to fuck with you.
The difficulty is totally bonkers too. You're easily too low leveled to beat anything, at their level and its an ok but still easy fight, or overleved and you steamroll the enemy. Not to mention the game is really lacking in content, even for a launch mobile game.