This is what happened to me and Ho-oh
I get up there,save,First time I OHKO him reset try again with typhlosion OHKO`d again then I reset set out my magnemite paralyze with static then just flamethrower him LV54 3 Times and I had 11 ultra balls,1 fast ball and my master ball.I threw the fast ball first failed 10 ultra balls later on my last ultra ball I say "Please Please Please Please" and it works :D and I nick named him OOOMMMGGG (Oh My God Oh My God Oh My God)