Sturdy Shedinja
![enter image description here](https://lh3.googleusercontent.com/-yXh-_2z5_u4/U-z4vkkw8TI/AAAAAAAANYU/ugqMy3lR4KA/w506-h379/Shedinja+day%2521+-+1)
Or any level one that learns leech seed. The only thing that really takes this down is weather or status. Give either of them a lum berry and you're good to go.
Flash Fire Ferrothorn
![enter image description here](/pokebase/qa-plugin/https-img-proxy/image.php?key=80e8ca653312db80&url=http%3A%2F%2F24.media.tumblr.com%2F91318c37d3db707a87cdb481dcc0b681%2Ftumblr_mg5hsameAB1r84emlo1_r1_500.gif)
Haven't seen this personally but apparently it can be a monster. Have fun killing this..
Toxic Heal Staraptor
![enter image description here](/pokebase/qa-plugin/https-img-proxy/image.php?key=3eb8bee8af1124c8&url=http%3A%2F%2F24.media.tumblr.com%2F5c62213301bda91bfbce2879fc9258b7%2Ftumblr_mk4pxzLhQa1rmtxh8o2_500.gif)
Give this thing toxic orb, facade and max out attack. That's all I need to say.
EDIT: as for the Flash Fire on Ferrothorn you could give Volt Absorb to a flying type or any ability that that makes a Pokemon immune to their weakness.
These are a few common abilities that I have seen or heard of. If you need more then ask :)