Crabs around melo melo spawn area /conflux #4 in grauberg. I capped mine there. Yes, it took very long time, soboro is very helpful. Also pick the atma properly. Apoc and Lion gives 25% triple attack rate, lion also gives 10% PDT. I usually /DNC for curing waltz, but Atma of the Mounted Champion also helps you to be in hasso stance most of the time.