WHY MAGERNA IS BROKEN
Defensive
While playing in OU I noticed something, the fact that magerna with the store-kiss set it was able to set on
Ferrothorn. With leftorvers magerna is able to sustain damage from ferrothorn and then retaliate with stored power.
(With 1 Shift gear and Calm mind)
+1 252 SpA Magearna Stored Power (120 BP) vs. 252 HP / 176+ SpD Ferrothorn: 68-80 (19.3 - 22.7%) -- possible 6HKO after Leftovers recovery
(With 2 Shift gears and Calm Minds.)
+2 252 SpA Magearna Stored Power (220 BP) vs. 252 HP / 176+ SpD Ferrothorn: 164-194 (46.5 - 55.1%) -- 14.1% chance to 2HKO after Leftovers recovery
So with enough setup magerna is able to setup on ferrothorn even with leech seed thanks to its leftovers recovery and the fact ferrothron is used to switch in or after mageerna gets a ko which then your baccically about to get swept.
Fire Types
Lets see the best check to magerna with this set, fire types. They completly destroy magerna.
252 SpA Heatran Magma Storm vs. +1 252 HP / 4 SpD Magearna: 194-230 (53.2 - 63.1%) -- guaranteed 2HKO after Leftovers recovery and trapping damage
252 Atk Cinderace Pyro Ball vs. 252 HP / 0 Def Magearna: 320-380 (87.9 - 104.3%) -- 25% chance to OHKO
252 Atk Life Orb Blaziken Flare Blitz vs. 252 HP / 0 Def Magearna: 429-507 (117.8 - 139.2%) -- guaranteed OHKO
252 SpA Blacephalon Flamethrower vs. +1 252 HP / 4 SpD Magearna: 194-230 (53.2 - 63.1%) -- guaranteed 2HKO after Leftovers recovery
+1 252 SpA Volcarona Flamethrower vs. +1 252 HP / 4 SpD Magearna: 270-318 (74.1 - 87.3%) -- guaranteed 2HKO after Leftovers recovery
So that seems a lot, but magerna has a great teamate to be able to check All of these. Garchomp.
Heatran
0 SpA Heatran Earth Power vs. 0 HP / 0 SpD Garchomp: 93-110 (26 - 30.8%) -- guaranteed 4HKO
252 Atk Life Orb Garchomp Earthquake vs. 252 HP / 0 Def Heatran: 811-957 (210.1 - 247.9%) -- guaranteed OHKO
Volcarona
+1 252 SpA Volcarona Bug Buzz vs. 0 HP / 0 SpD Garchomp: 259-306 (72.5 - 85.7%) -- guaranteed 2HKO
252 Atk Life Orb Garchomp Stone Edge vs. 0 HP / 4 Def Volcarona: 801-946 (257.5 - 304.1%) -- guaranteed OHKO
Cinderace
252 Atk Life Orb Garchomp Earthquake vs. 0 HP / 4 Def Cinderace: 269-317 (89.3 - 105.3%) -- 31.3% chance to OHKO -
Without its fire type
252 Atk Cinderace Pyro Ball vs. 0 HP / 4 Def Garchomp: 93-111 (26 - 31%) -- guaranteed 4HKO
252 Atk Libero Cinderace High Jump Kick vs. 0 HP / 4 Def Garchomp: 204-241 (57.1 - 67.5%) -- guaranteed 2HKO
Blacephalon
252 SpA Blacephalon Flamethrower vs. 0 HP / 0 SpD Garchomp: 94-111 (26.3 - 31%) -- guaranteed 4HKO
252 Atk Life Orb Garchomp Earthquake vs. 0 HP / 0 Def Blacephalon: 704-834 (285 - 337.6%) -- guaranteed OHKO
Blaziken
252 Atk Life Orb Garchomp Earthquake vs. 0 HP / 4 Def Blaziken: 569-671 (189 - 222.9%) -- guaranteed OHKO
252 Atk Life Orb Blaziken Close Combat vs. 0 HP / 4 Def Garchomp: 251-296 (70.3 - 82.9%) -- guaranteed 2HKO
So besides blaziken with its close combat, and volcarona with its bug buzz, garchomp is a solid check to these pokemon
Ground Pokemon
My boys. But anyways there typing they are able to threaten magerna, hippowdown is able to check her due to the fact that it can phase it.
+1 252 SpA Life Orb Magearna Draining Kiss vs. 252 HP / 0 SpD Hippowdon: 208-247 (49.5 - 58.8%) -- 99.6% chance to 2HKO
252 SpA Life Orb Sheer Force Nidoking Earth Power vs. +1 0 HP / 4 SpD Magearna: 221-265 (73.4 - 88%) -- guaranteed 2HKO
252 Atk Excadrill Earthquake vs. 0 HP / 0 Def Magearna: 300-354 (99.6 - 117.6%) -- 93.8% chance to OHKO
252 Atk Landorus-Therian Earthquake vs. 0 HP / 0 Def Magearna: 314-372 (104.3 - 123.5%) -- guaranteed OHKO
252 Atk Life Orb Garchomp Earthquake vs. 0 HP / 0 Def Magearna: 377-447 (125.2 - 148.5%) -- guaranteed OHKO
0 Atk Swampert Earthquake vs. 0 HP / 0 Def Magearna: 206-246 (68.4 - 81.7%) -- guaranteed 2HKO
But even with all of these Rillaboom and its grassy terrain has the ability to kill almost all of them.
252+ Atk Choice Band Rillaboom Grassy Glide vs. 0 HP / 0 Def Nidoking in Grassy Terrain: 295-348 (97.3 - 114.8%) -- 81.3% chance to OHKO
-1 252+ Atk Choice Band Rillaboom Grassy Glide vs. 0 HP / 12 Def Landorus-Therian in Grassy Terrain: 171-202 (53.6 - 63.3%) -- guaranteed 2HKO
252+ Atk Choice Band Rillaboom Grassy Glide vs. 0 HP / 4 Def Excadrill in Grassy Terrain: 357-421 (98.8 - 116.6%) -- 93.8% chance to OHKO
252+ Atk Choice Band Rillaboom Grassy Glide vs. 252 HP / 4 Def Swampert in Grassy Terrain: 1036-1224 (256.4 - 302.9%) -- guaranteed OHKO
252+ Atk Choice Band Rillaboom Grassy Glide vs. 0 HP / 4 Def Garchomp in Grassy Terrain: 247-292 (69.1 - 81.7%) -- guaranteed 2HKO after Grassy Terrain recovery
252+ Atk Choice Band Rillaboom Wood Hammer vs. 252 HP / 248+ Def Hippowdon in Grassy Terrain: 524-618 (124.7 - 147.1%) -- guaranteed OHKO
So besides lando-t with intimidate which can't switch into wood hammer, rillaboom checks all of these.
Steel Types
So besides Hetran and Exadrill , (Which I've covered), other steel types can stall it out right?
+1 252+ SpA Life Orb Magearna Stored Power (120 BP) vs. 252 HP / 252+ SpD Corviknight: 112-131 (28 - 32.7%) -- 82.6% chance to 4HKO after Leftovers recovery
+1 252+ SpA Life Orb Magearna Stored Power (120 BP) vs. 0 HP / 4 SpD Kartana: 333-391 (128.5 - 150.9%) -- guaranteed OHKO
252 Atk Life Orb Kartana Sacred Sword vs. 0 HP / 0 Def Magearna: 147-173 (48.8 - 57.4%) -- 94.1% chance to 2HKO
252+ Atk Choice Band Iron Fist Melmetal Double Iron Bash (2 hits) vs. 0 HP / 0 Def Magearna: 372-438 (123.5 - 145.5%) -- guaranteed OHKO
Yeah so with the defensive set, besides Kartana Magearna loses easily. But magerna is known with its versatility, and that is what it has.
252+ Atk Choice Band Iron Fist Melmetal Double Iron Bash (2 hits) vs. 0 HP / 0 Def Magearna: 372-438 (123.5 - 145.5%) -- guaranteed OHKO
But Magerna is almost unstoppable with grassy terrain when it comes with these, considering that rillaboom already checks most of these.
Blissey
So you might be wondering what about the blobs you know the most hated pokemon in history, but magerna has a vital immunity to toxic so lets see how it does.
(With 1 Shift gear and Calm mind)
+1 252 SpA Magearna Stored Power (120 BP) vs. 252 HP / 4 SpD Blissey: 151-178 (21.1 - 24.9%) -- guaranteed 5HKO
+1 252 SpA Magearna Draining Kiss vs. 252 HP / 4 SpD Blissey: 94-112 (13.1 - 15.6%) -- possible 7HKO (23.5 - 27.9% recovered)
So it seems like magerna is screwed against this blob until you realize that magerna recovers enough health to outdo the seismic toss damage with draning kiss and leftovers, and the additive health that it will get allows magerna to setup with careful strategy.
Some Other Mons.
+1 252+ SpA Magearna Stored Power (120 BP) vs. 252 HP / 112 SpD Toxapex: 294-346 (96.7 - 113.8%) -- 81.3% chance to OHKO
+1 252+ SpA Magearna Draining Kiss vs. 252 HP / 0 SpD Buzzwole: 446-528 (106.6 - 126.3%) -- guaranteed OHKO
+1 252+ SpA Life Orb Magearna Draining Kiss vs. 0 HP / 4 SpD Multiscale Dragonite: 175-207 (54.1 - 64%) -- guaranteed 2HKO
+1 252+ SpA Life Orb Magearna Draining Kiss vs. 0 HP / 4 SpD Dragapult: 439-523 (138.4 - 164.9%) -- guaranteed OHKO
+1 252+ SpA Life Orb Magearna Stored Power (120 BP) vs. 0 HP / 4 SpD Magearna: 123-146 (40.8 - 48.5%) -- guaranteed 3HKO
So in conclusion Magearna's "checks" can be ko'd and Magearna will just sweep with no recource.