This is what i do to stay in top 10 as an f2p player:
Complete all level 2 magatamas then rack up to 600 coupons for refine. Refine is a lot more important imo. I faced a lot of ppl with lvl 3 magatamas but can't seem to make a comeback i hit first coz of refine's initiative. That's if you have a cc team. I even beat ppl with pains and iruka.