OK you want to tall you my reasons, Nothing can stand in the way of blizzard/draco meteor, most stuff is OHKO by it and do you really want a metagame where one poke can revenge everything, Chansey can wall him all day if special, but with the right support it's impossible to stop, even the mixed set is not possible for her to stop, don't tell me that fighting and rock stop him since wit pure power he kills everything, nothing can swich in if not loosing a bug chuck of health, and not a lot of usefull thing can come an revenge (every steel is 2HKO bar registeel), don't believe me, here are some calcs:
Focus Blast vs 252/4 Bold Chansey 39.2% - 46.3%
Focus Blast vs 252/4 Bold Blissey 42.3% - 49.9%
Draco Meteor vs 252/4 Bold Milotic 78.7% - 92.9%
Draco Meteor vs 252/252 Calm Milotic 58.9% - 69.5%
Ice Beam vs 252/136 Calm Roserade 121.0% - 143.2%
Draco Meteor vs 252/136 Calm Roserade 88.9% - 104.9%
Ice Beam vs 4/252 Adamant Birijion 104.3% - 124.1%
Draco Meteor vs 4/252 Adamant Birijion 76.9% - 90.7%
Focus Blast vs 252/252 Careful Snorlax 55.7% - 65.6%
Focus Blast vs 252/252 Calm Probopass (Sandstorm) 96.3% - 113.6%
Focus Blast vs 252/200 Careful Registeel 65.9% - 78.0%
Draco Meteor vs 4/252 Timid Gardevoir 97.5% - 114.7%
Focus Blast vs 252/252 Calm Tabunne 82.9% - 98.0%
Focus Blast vs 120/252 Careful Umbreon 72.0% - 84.8%
Focus Blast vs 252/216 Sassy Bronzong 42.6% - 50.3%
Draco Meteor vs 252/216 Sassy Bronzong 37.3% - 43.8%
Hidden Power Fire vs 252/252 Sassy Bronzong 53.3% - 62.7%
everything not named chansey/blissey is 2HKOed, i'm using him in stall and he can take hits and dragon tail away, it's verstile and too powerfull to be here (whit cond and the likes gone he can sweep easily), also It only needs 52 HP EVs to have 101 HP subs, meaning it turns Chansey from a stop to set up fodder, making her his bitch without even trying, Kyu can function as a Specs hit and run poke, a scarfed revenger, a bulky sweeper, a mixed LO stall-breaker and a phazer. It has a large amount of options and I don't see any poke that can handle all of them at once.