Somokai

Thank you all for your suggestions! It was so difficult deciding what to choose because I had no idea what to expect from future battles I'll take what all of you said into consideration

So I've been playing through reborn and I've gotten to the academy on the other side of the azurine lake. I got lucky with finding an Axew egg as the police man sidequest reward and I really really wanna get that beautiful haxorus for my team. So my question is, should I go for an adamant or jolly nature and should I get mold breaker or rivalry as I'm not sure what'll be more useful. PLEASE NO SPOILERS!!!! Thank you all in advance