I use the exact same trick> :-D
I like Monster Houses. I just use a burning Heat Wave and kill them all.
same here legendaries rockBlizzard only effects the Pokemon in front of you. o_o
I just use Powder Snow on 'em with my Articuno, Dei. If the moves misses any, then I'll use a normal attack, which'll do 100+ damage.
Shedinja has 5 HP, takes only 1 damage from regular attacks, and immune to other attacks except for Super-Effective hits.