I think the game has been steadily losing players for the past few months; even the number of views for the forum's patch notes is less than before. The numbers for global VF pre-registration are on the low side (and honestly I don't think VF is ready yet - you will get a negative backlash if you release this game in its present state to a global audience as initially players will enjoy the game for the first few weeks but eventually get frustrated, disappointed and quit, and the American market will be more vocal than the SEA or TW market, which means you get even more negative publicity).
I think any game designer would want to maintain/increase the benefit and fun factor while reducing the frustration and repetitiveness of their game. This will ensure a healthy player base for their revenue and profits. The returns/enjoyment of the customer should be commensurate with the amount of time, energy and money spent, otherwise the customers will leave. Of course, it's not always easy to strike this balance and "fun" can be quite subjective but that's why you have a bit of something for everyone, or you focus only on a specific group of players -- however, I understand that mobile games are generally casual-friendly.
Developers are focusing on relatively unimportant matters such as Rune Merge and Hero Merge when they need to be focusing on more critical areas, as they botched up the implementation/execution of the most recent big changes to the game, namely Summoners and Guild Raid (hyped up "beta" testing on live server to the whole user base which destroyed guilds, OMG, and Leon/Theia to a lesser extent). If your ship is sinking, you don't go and upgrade the IT systems of the ship. You need to be making changes similar to the implementation of Valianite to reduce player frustration.
There have been so many good suggestions in the forum but I don't see developers working on many of them, or you are taking too long. I think you need to improve the following ASAP:
1. Valiant Revamp: Making old heroes obsolete so quickly is one of the surest ways to frustrate and kill the fun for players. I'm guessing this is a bit of firefighting because it should not be taking you this long to come out with the Valiant revamp when you ought to have known how summoners would have affected the gameplay and balance of the game, especially in arena. I still find it hard to believe your internal testing didn't pick up how stupidly overpowered the summoners could be. (And why must you make us wait 3 secs each time we summon?)
2. Introduce new content and do a better job with it. The events introducing the last 5 summoners are all more or less the same thing. Leon/Theia was a fantastic opportunity to improve player stickiness/retention and introduce some new gameplay and storyline elements (lots of ideas in forums), but it was basically a repeat of what we'd seen before. Theia's 5* aura was especially disappointing.
3. Fix the Guild Raid in-game communication and rewards system. You are the first RPG I've ever played that still doesn't have a fully functioning in-game chat so many months later after release. Not all players even know that there is a guild chat function; no info/tutorial for it when you first start playing. Also, many of us TOLD you from the beginning that having a tiered internal guild reward system was a bad idea but you didn't listen and now we are experiencing those problems. This does not bode well for the future of the game.
4. Reduce the amount of repetitiveness in the daily quests e.g. gold mine X 3 or 6 or whatever. I know this is in the works already but hurry up and implement it, please. Also hope you will improve express ticket functionality as previously suggested. The Guild Raid is also rather grindy/repetitive. Just give us 1 raid key a day and reduce the boss HP accordingly. It gets boring to have to run it twice a day every day--I no longer look forward to doing so-- especially when it can take weeks to months to see any improvement to your party. The game should be built to fit around our daily lives; not the other way around.
5. Your expectation management and communications to the player base about gameplay changes... For example, are we supposed to expect that eventually our old heroes will become obsolete? Or managing expectations for 100% event quest completion which is RNG-dependent and is inconsistent with earlier messages sent when players first start the game where we are conditioned to be able to complete 100% of all quests. Furthermore, Rune Merge is not relevant to most of the player base, so why did you hype it up so much unless you want players to be disappointed? Even Hero Merge is rather disappointing and expensive; the only part that makes sense is for the 5* hero part, where you can either get a useful 5* hero or a 5* fodder for aura re-reroll, but it's more costly than doing 400 premium gem summons or leveling up a 5* fodder (except job keys). And the soul binders can't be used as training fodder either.
6. There are still some basic design issues that haven't been addressed which have been mentioned in the forums. For example, certain classes are just not used that often such as healers or mystics; it's mostly ranger/warrior (with a bit of guardian). And somehow shadow's best role is to be a gold miner? In Legendary Story Mode, healers and guardians still suffer from the same problem as before. By the time they are able to heal or taunt (5-7 turns later), most, if not all of the team is already dead -- enemy mobs crit often and can even one-shot 3-4K defense heroes (the boss). Players have to artificially rebalance the game by keeping 1 last mob alive while waiting for the turn counter to pass by before entering the boss round; or are forced to build the team aggressively (e.g. trigger teams) to kill off the monsters before they kill the party, since balanced or defensive team compositions don't work.
7. Packages in the shop are too pricey.... I really would like to support the game but I feel so turned off whenever I see those prices. ~$150-180 for a partially decked out hero (and we can't choose summoners from the selector)? So a team of 5 heroes will cost $900+?? Yet the game is designed in a way where we can't keep using the same 5 heroes? How many of you would spend that kind of money yourselves on a mobile game? You know how much content one can get for that kind of money playing other MMORPGs from other companies?
Great art, voices and music can only do so much.