What it could've been:
252+ Atk Choice Band Crabominable Ice Shard vs. 0 HP / 0 Def Garchomp: 456-540 (127.7 - 151.2%) -- guaranteed OHKO
-1 252+ Atk Choice Band Crabominable Ice Shard vs. 0 HP / 4 Def Landorus-T: 316-376 (99 - 117.8%) -- 93.8% chance to OHKO
252+ Atk Choice Band Crabominable Ice Shard vs. 0 HP / 4 Def Multiscale Dragonite: 228-270 (70.5 - 83.5%) -- 56.3% chance to OHKO after Stealth Rock
252+ Atk Choice Band Iron Fist Crabominable Mach Punch vs. 0 HP / 4 Def Terrakion: 288-338 (89.1 - 104.6%) -- 31.3% chance to OHKO

REALITY:
>No priority to touch these threats
252 SpA Life Orb Garchomp Fire Blast vs. 252 HP / 0 SpD Crabominable 624-738 (156.7 - 185.4%) -- guaranteed OHKO
252 Atk Landorus-T Superpower vs. 252 HP / 0 Def Crabominable 352-416 (88.4 - 104.5%) -- 31.3% chance to OHKO
252 Atk Terrakion Close Combat vs. 252 HP / 0 Def Crabominable 486-572 (122.1 - 143.7%) -- guaranteed OHKO
252+ Atk Choice Band Dragonite Outrage vs. 252 HP / 0 Def Crabominable 409-483 (102.7 - 121.3%) -- guaranteed OHKO

What a piece of shit. Biggest disappointment this gen?