Check out this bad boy.
@ Life Orb / Tyranitarite
Ability: Sheer Force
252 Atk / 252 Spe / 4 Def
Jolly Nature
- Diamond Storm
- Crunch
- Sucker Punch / Fire Punch
- Dragon Dance / Taunt
A Dark type without Knock Off? I know, I know. Hear me out. Sheer Force Crunch is slightly stronger than the first Knock Off and much stronger than the second. The downside of course if you no longer remove the target's item, but I think the power output is worth it. Diamond Storm is Tyranitar's strongest attack and can easily 2HKO a fully defensive Chansey
without any boosts. Sucker Punch is good to have before you get enough Speed boosts and makes it a fantastic revenger. Fire Punch was just subbed for coverage--another move might work better. Dragon Dance might seem counter-intuitive with Unaware and Prankster as two of the more common abilities (probably) but late game it can help clean up especially once you mega evolve. Taunt is extremely viable and can screw over a switch-in Prankster hoping to Topsy, Parting Shot, Dark Void, WOW, etc. Check out Sheer Force's damage output in the calcs below.
Calcs:
252 Atk Life Orb Sheer Force Tyranitar Crunch vs. 252 HP / 252+ Def Cresselia: 289-343 (65 - 77.2%) -- guaranteed 2HKO after Leftovers recovery (Unaware is dead no matter what, Poison Heal has a chance to Protect and heal out of the 2HKO range, but will be facing immense pressure)
252 Atk Life Orb Sheer Force Tyranitar Diamond Storm vs. 252 HP / 252+ Def Spiritomb: 192-227 (63.1 - 74.6%) -- guaranteed 2HKO after Leftovers recovery (If it's Prankster, Taunt is the best move to use as it comes in)
+1 252 Atk Life Orb Sheer Force Tyranitar Diamond Storm vs. 252 HP / 252+ Def Suicune: 277-328 (68.5 - 81.1%) -- guaranteed 2HKO after Poison Heal (Needs to be at +1 and good health otherwise will lose from Scald and burns. Scald does 46.3 - 55.1%)
252 Atk Life Orb Sheer Force Tyranitar Diamond Storm vs. 252 HP / 252+ Def Mandibuzz: 398-468 (93.8 - 110.3%) -- 62.5% chance to OHKO (Will probably be Prankster. Stealth Rocks is a guaranteed OHKO)
252 Atk Life Orb Sheer Force Tyranitar Diamond Storm vs. 252 HP / 252+ Def Eviolite Chansey: 374-442 (53.1 - 62.7%) -- guaranteed 2HKO (Unaware loses. Prankster will Transform and Diamond Storm will do 18.3 - 21.5% to it. Chansey can win if it still has its Eviolite)
This is pure theorymoning, but I'll probably test it out soon.