Gold Shortage
I'm sure as I post this it'll be very controversial for some odd reason, just due to the fact that so many people grind arenas. However, for those that realize the fact that the arenas are absolutely absurd, we tend to run out of gold... A lot. With the ability to now rank up your your 6* up to rank 4 at a "measley" 811,390 gold. Plus probably another 800k gold for upgrades. It's an insane amount for a single rank. Throughout the game these higher catalysts have become more obtainable. With duplicating champions, large quantities of iso has become more obtainable, but gold is still an absolute grind. So my suggestion here is, why not make gold more accessible in large quantities. When it comes to upgrades gold is used for literally everything and especially nowadays an over the top amount is needed. Instead of making it a pay-to-play kind of thing (gold pool quest for buying the monthly sigil) make it a daily quest like it is for the smaller catalyst. That or make halls of fortune more frequent.