Originally Posted by Fat Doom Chaos
Magikarp is getting Hydro Pump via a Japanese Event, but the Magikarp is only available at level 99, so it is illegal in LC. It remains legal in OU, its best tier.
STAB Hydro Pump in the rain (teammate's Rain Dance or opponent's rain, because Swift Swim + Drizzle is banned) is gonna plow through the biggest defensive behemoths in OU like Rhyhorn or Geodude, and even the unbelievably bulky Magcargo.
252 SpAtk Choice Specs Magikarp (+SpAtk) Hydro Pump in the rain vs 252 HP/252 SpDef Magcargo (+SpDef) : 189,47% - 223,03%
Worth updating the analysis a little imo.
OU? Pfft, Magikarp for Ubers mate.
252+ SpA Choice Specs Magikarp Hydro Pump vs. 248 HP / 84 SpD Ho-Oh in rain: 228-270 (54.93 - 65.06%) -- guaranteed OHKO after Stealth Rock