A lot of other f2p games I play have some sort of feature to ensure players don’t consistently get screwed over by bad RNG and discouraged from playing. Given how much frustration there is around the odds, I believe this game could benefit from something like this quite a bit.
A high-level example would be if there’s a 1% chance of pulling a 5-star hero, then every 100th pull should be a guaranteed 5-star pull. That countdown can be reset every time a legendary hero is pulled ahead of it for balance.
Iono, just spitballing here.