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Just a reminder that HP ground hits rock types super-effective as well. However, other fire/flying or levitating pokemon will like that more than techno-surf as they are immune but is that move used instead of tbolt? if not then tbolt will cover most flyers.
I don't have anyone that can vouch for me but I trust you so if you want, we can trade the haxorus for some random poke (bunnelby or something useless) and you can check it then if you are satisfied, trade the ferro for the crap pokemon back? I only joined smogon for the wifi battle finder to be...