Sun kiss

Im not talking about cs outfits, I mean like the ones under Viridian coast, and the cinderlands for example. How do you obtain those? I know few is from spinning those wheels with field bosses, but how can you obtain the rest? Also, what's a good OP class? Like something even the worst player can play easily and win with lmao. I'm a returner but I forgot how most things work. Oh! One more question, how do you upgrade your equipment other than through story?