Metagross-Mega @ Metagrossite
Ability: Tough Claws
EVs: 252 Atk / 4 SpD / 252 Spe
Jolly Nature
- Meteor Mash
- Hammer Arm
- Power-Up Punch/Zen Headbutt
- Bullet Punch/Earthquake/Grass Knot/Ice punch...
Considering Skamory is a metagross switch-in here, there are two possibilities to get rid of skarm with this set.
1° - Power-up-punch on the switch-in/on spikes (14 - 16.7%).
Turn 2 ; Hammer Arm (52.6 - 62.2%) :
if whirlwind, skarmory will be left at (39,4 -27,1%) of his life (including leftovers) and therefore is easily revenge killable,
if spikes it's a 2hko and
if roost, metagross just has to hammer arm again next turn to be slower than skarm and then prevent him from using roost (OHKO at +1 and without the flying type).
2° - Hammer Arm on the switch-in/on spikes (35 - 41.3%). Turn 2 : Hammer Arm (35 - 41.3%) and Metagross becomes slower than Skarmory,
if whirlwind, skarmory will be left at
(42 - 29,4%) of his life (including leftovers recovery) and therefore is easily revenge killable,
if roost --> Turn 3 : Skarm plays first so if roost, it dies on the hammer arm and if whirlwind, it will be left at (63 - 44,1%) of his life.
All the calcs do not include Stealth rock damages (just remove 12,5% to get them).
The 1°, with power-up-punch prevents skarmory from setting spikes and guarantees an easy revenge kill (assuming you're not playing stall).
The 2° does the same as the 1° but may be less effective if your opponent plays good.
(Yes Thunder Punch also works but Hammer Arm has a larger coverage)
I hope I haven't been too confusing in my post; calcs have confused me ù_ù