I have some ideas to improve this game, I hope to be of help to developers.
1 - for the winners of the events PVP and PVE, release a cover 4 * player’s choice is as a character than as color. (given the large number of characters 4 *, it seems to me an appropriate solution to bring a character to the top and not have to wait months for a cover).
2 - Specify the event rules PVE as are carried out: how many sub events, duration of sub events etc.
3 - Characters: give the possibility to have all 15 covers of characters available and pick 13 to play, so you can differentiate the strategy depending on the characters we play.
4 - How to read in some forums to increase the number of lives left (the meetings are much more expensive now than before).