252 SpA Hydreigon Black Hole Eclipse (640 BP) vs. 252 HP / 252+ SpD Blissey: 592-697 (82.9 - 97.6%) Hey you can tank it consistently even without AV…
unless it’s +spatk then 252+ SpA Hydreigon Black Hole Eclipse (640 BP) vs. 252 HP / 252+ SpD Blissey: 649-765 (90.8 - 107.1%) -- 43.8% chance to OHKO. But chansey doesn’t even need full investment to tank it 252+ SpA Hydreigon Black Hole Eclipse (640 BP) vs. 116 HP / 140+ SpD Eviolite Chansey: 568-669 (84.7 - 99.8%) -- guaranteed 2HKO