How to increase spawn rates + some quetions

so ive een playing bromons for about a month now and I have almost all the common ones and even 2 rares and a few uncommon. i was wondering A what the formula for spanw rates is and how to increase spawn rates. and B how does the game decide what bromon to spawn? if I have all commons will a rarer one spawn? just now I had a mythical appear ( the cat one (sorry for not knowing the name) ) and I tried to fight it with my rare redditor and obviously lost but I was wondering if there’s like a way to wineven more unfair fights or wether its all luck. also what happens if I ignore the mythical? will a worse one spawn? thanks in advance!

Same, I have an epic and now I have seen rarely spawned Bromons. I only see commons

Luck

Yea… luck…

Why does everybody think there is some sort of cheat… the best way to play something is to do it how you are supposed to… not to find a way to make it faster or easier…