I synchronized it with a timid umbreon, mean looked it, then baton passed it.I forgot how I did it exactly, but I think I used my watchog to mean look it, and used hypnosis to sleep. I kept my watchog at 39, but thundurus didn't really kill it anyways. You can then attack it, or use super fang, if it got it at that level. Or run into it a few times, and do 1 attack, let it flee, do another attack, let it flee, until it's down. Then use mean look.
Then after the nature wouldn't work, I said screw it and used a master ball every time. Settled for hasty nature.










