i loved this mode, although this is the most hectic mode of the game, My little suggestion is that the players who play this mode regularly must be rewarded daily in addition to the end of event chest. Like it is done in other modes eg. hero arena, festival we get daily coins depending on their daily standing.
The most appropriate award in my opinion would be a decent amount of gold since the gold is already scarce in the game or daily mythical dust (that might be too much to ask for). I seriously believe the daily gold incentive would increase the number of daily players in this mode.