>>20261814He's also overlooking that Jolly Char X can OHKO Lando-T at +0 (31% chance) which becomes guaranteed with SR up (which is often used to break sashes anyway). Investing like 200 hp evs will make it survive pretty reliably though.
252 Atk Tough Claws Mega Charizard X Flare Blitz vs. 4 HP / 0 Def Landorus-T: 286-337 (89.3 - 105.3%) -- 31.3% chance to OHKO
252 Atk Tough Claws Mega Charizard X Flare Blitz vs. 4 HP / 0 Def Landorus-T: 286-337 (89.3 - 105.3%) -- guaranteed OHKO after Stealth Rock
252 Atk Tough Claws Mega Charizard X Flare Blitz vs. 200 HP / 0 Def Landorus-T: 286-337 (77.5 - 91.3%) -- 31.3% chance to OHKO after Stealth Rock
252 Atk Tough Claws Mega Charizard X Flare Blitz vs. 252 HP / 0 Def Landorus-T: 286-337 (74.8 - 88.2%) -- 6.3% chance to OHKO after Stealth Rock
I'd actually just sacrifice whatever it is that's currently out and try to do some damage as Char X dances. Revenge kill afterwards with Scarfchomp or Talonflame.
At one point, I got tired of dealing with Charizard that I just included Chansey as a switch-in. I win the clash if it's Y, I can survive a +1 Outrage/FB and Thunderwave back if X. If it flare blitzes me on the switch-in, at least it almost kills itself so priority can finish it off.