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I did misread but i'd still recommend using expert belt or band or more attack evs in genereal so you cant beat him any case. About Groudon it fits way better in this team than Ho-Oh but it's what i said, you'd have to change the whole team to get Ho-Oh wich is a Nuke with free regen on this...
Honestly, what rank did you get with this?
Solgaleo-You're saying you rely on a crit to beat ZGeo Xern and it's problably true since he will Moonblast it until he is in range of sweep and you lost. I'd reccomend using Max atk(natures are based of % so addamant is useless, you'll 3KO anyway) and...