I think this guy was overlooked for a long time. He's a wall, that is true, but with steel resisting fairy and at the same time being super effective against it, registeel has been able to be a legitimately unstoppable sweeper. Some dual screen assistance can be even more lethal, as the set-ups this guy can produce are enough to actually sweep entire full teams. I used a dual screening cresselia before I sent him out but that's not necessary, as i decided not to even do that sometimes. Here's my set, and don't knock it 'till you try it, this set kills.
Set-Up Sweeper
Ability: Clear Body
252 HP, 130 Def, 130 SpD
Item: Leftovers
Nature: Adamant
Toxic
Curse
Iron Head
Amnesia
I like adamant nature because I use him as a sweeper, and his Iron Head really benefits from this. He has more than enough bulk to set up. Leftovers are essential, as they are his only method of HP recovery. He's immune to poison, so burns are really his only enemy. You can Toxic the enemy if you'd like, and set up Amnesia against a special attacker 2-3 times. Then start using Curse, which boosts your Attack to usable levels at +2, let alone +6. You'll have plenty of bulk for these 9 set-up moves, once that happens, the enemies attacks will do less than leftovers recovery. Once you're all set up, IRON HEAD. You're done.
(Side note: Initially, I thought that curse wouldn't lower my speed through Clear Body, but it does for some reason. Speed is really unimportant though)
I considered Air Balloon, but Leftovers are too valuable once you're all set up.
Set-Up Sweeper
Ability: Clear Body
252 HP, 130 Def, 130 SpD
Item: Leftovers
Nature: Adamant
Toxic
Curse
Iron Head
Amnesia
I like adamant nature because I use him as a sweeper, and his Iron Head really benefits from this. He has more than enough bulk to set up. Leftovers are essential, as they are his only method of HP recovery. He's immune to poison, so burns are really his only enemy. You can Toxic the enemy if you'd like, and set up Amnesia against a special attacker 2-3 times. Then start using Curse, which boosts your Attack to usable levels at +2, let alone +6. You'll have plenty of bulk for these 9 set-up moves, once that happens, the enemies attacks will do less than leftovers recovery. Once you're all set up, IRON HEAD. You're done.
(Side note: Initially, I thought that curse wouldn't lower my speed through Clear Body, but it does for some reason. Speed is really unimportant though)
I considered Air Balloon, but Leftovers are too valuable once you're all set up.
