Deck Knight
Blast Off At The Speed Of Light! That's Right!
LOL @ 4x effective attack not doing 25% damage. Skymin has 100/75/75 defenses. Please, Registeel isn't that weak. Do some Calcs.Ice Punch can't even break Skymin's sub if it's running HP EV's, and good luck trying to even use it with a 40% chance of moving.
Aerodactyl seems like a potential counter, but if Skymin has a sub up and air slashes when Aerodactyl switches in, Aero's done.
I did No EV Ice Punch on 8/0 Tropius with 15 Defense IV, which has the same HP/defense as a 0/0 Skymin.
Result: 64-76%.
Yeah, SubSeed Shaymin would be pretty annoying, but with only a little EV Investment Registell can get it below 25% HP, removing any chance of it being able to Sub.
Registeel with 120 Atk EVs vs. 0/0 Skymin: 75-88%. That's a OHKO with Stealth Rock out.
Anti-Skymin Registeel:
Registeel @ Leftovers
252 HP/120 Atk/136 Def
Nature: Careful
~ Ice Punch
~ Stealth Rock
~ Rest
~ Thunder Wave/Amnesia/Sleep Talk.
Timid Skymin 252 SA Seed Flare on aforementioned Registeel:
16-19%
Timid Skymin 252 SA Air Slash:
10-12%
Timid Skymin 252 SA HP Ground:
26-30%. 4HKO Tops.
So yeah, SubSeed Shaymin would be highly annoying, but Registeel can set down rocks and then Ice Punch later. In the meantime, it can easily PP Stall or Rest-stall.