>>54176180Iron Bundle has unresisted STAB with Freeze Dry and Hydro Pump. 136 speed is also excessive on a Pokemon that hits that hard.
Chien-Pao is an unfortunate victim of shit rolling down the hill. Flutter Mane and Houndstone getting banned let Iron Bundle run roughshod. Iron Bundle then had to be banned, so Palafin had to go too since Iron Bundle was its one counter. Palafin and Bundle being banned meant Chi-Yu was now too much as the Water types that kept in check got flushed, so it's gone now too. With Chi-Yu, Palafin, Iron Bundle, and Flutter Mane gone, Chien-Pao had no checks or counters left in the tier so it get kneecapped as well.
Having a super special ability that effectively gave it Kartana's Attack stat while having 135 speed definitely didn't help its case.