I think one of the issues is that the game lacks depth?
1) The events generally are like "Use the event unit to clear unless you wanna spend x items every time you wanna clear the stage", I mean I understand that you guys gotta earn some profit, but couldn't it be like "Event units get more event currency (not points)" or "Event units skills work well against the boss" instead of "Boosting the stats of the event unit to the extent you can auto the stages if you had 2 of them".
2) The stats of the game work exponentially, meaning that if you can't hit a certain amount, you'll be dealing peanuts and coking on glass shoved by enemy mobs. It becomes more of a stats race instead of strategy making. My old guild quit and moved on to Valkyrie Connect because they eventually got sick of this aspect of the game.
3) The characters are interesting, but they lack character, no pun intended, having side quests where you can explore the characters relationships with each other, or how they came to be would be entertaining and would give people that have fused/promoted/upgraded all their stuff something to do.
4) Challenges would be fun too, like a extra difficult (non-time limited) boss stage where people could chunk a large potion of their energy in to try and overcome a boss for strong equipment or what not.
5) Giving equipment passive abilities would also make the game more interesting, much like the raid set, if there were equipments that grant an extra aura skill or other passives like an extra aura direction, a fixed percentage increase in a stat (like the heirloom sets) would make for more interesting builds.
The game is awesome and the devs are really nice people that actually listen, it would be a shame if the game lost their players. Personally I think mindless gameplay can only last for a while, the best games are usually the one with the best stories, just look at Last of Us, Nier, Heavy Rain, the final fantasy series, and Witcher.
Tl/dr : Add depth to the game in terms of strategy and character development, don't make it a mindless stats competition.
P.S. Dude seriously, the event stat boosting is annoying, it doesn't freaking make sense that a player that have played for 1 month can clear stages that someone that have played for 3 months can't just because they had the event unit.
