>>44476943252+ Atk Cinderace Pyro Ball vs. 200 HP / 252+ Def Blissey: 361-426 (51.4 - 60.7%) -- guaranteed 2HKO
It may not 2HKO Eviolite Chansey without a boost, but it does 2HKO Blissey, which now is the preferred blob.
Also, Cinderace has Bulk Up, which offsets the eviolite boost, and High Jump Kick
+1 252+ Atk Cinderace Pyro Ball vs. 248 HP / 252+ Def Eviolite Chansey: 396-466 (56.3 - 66.2%) -- guaranteed 2HKO
252+ Atk Libero Cinderace High Jump Kick vs. 248 HP / 252+ Def Eviolite Chansey: 572-674 (81.3 - 95.8%) -- 56.3% chance to OHKO after Stealth Rock
Oh, and Gunk Shot/Pyro Ball still have a 2% chance to 2HKO Chansey after rocks
252+ Atk Cinderace Pyro Ball vs. 248 HP / 252+ Def Eviolite Chansey: 264-312 (37.5 - 44.3%) -- 2% chance to 2HKO after Stealth Rock
And a 99% chance after Stealth Rock+1 layer of Spikes
252+ Atk Cinderace Pyro Ball vs. 248 HP / 252+ Def Eviolite Chansey: 264-312 (37.5 - 44.3%) -- 99.6% chance to 2HKO after Stealth Rock and 1 layer of Spikes
There is also nothing Chansey or Blissey can really do to Cinderace besides waste it’s PP (which wastes their own) and toxic it when it’s not a poison type.