I just use iron defense ferro. Most teams dont have dual weather or another fire type besides incin, but even than the rain and being at +4 makes it do very little. Its not perfect though. There was recently a sun and rain teams than won something (I forgot the specifics) so that team/variants of that team have been popping up a bit, so that kind stops it. You can also try palkia TR. Palkia has a ×4 resist and isnt weak to ice beam or thunder.
Than again im bad at vgc in general so :P