Last one was in January and wasn't well laid-out.
Registeel (Steel)
Base Stats: 80 HP / 75 Atk / 150 Def / 75 SAtk / 150 SDef / 50 Spd
Ability: Clear Body
Notable Physical Movepool
Iron Head
Superpower
Arm Hammer
Focus Punch
Brick Break
Explosion
Aerial Ace
Shadow Claw
Rock Slide
Seismic Toss (Emerald Tutor)
Thunderpunch (Emerald Tutor)
Ice Punch (Emerald Tutor)
Notable Special Movepool
Luster Cannon
Focus Bomb
Charge Beam
Thunderbolt
Thunder
Notable Support Movepool
Thunder Wave
Stealth Rock
Psych Up
Safeguard
Registeel got the short end of the Registick for the most part, but due to the advent of Choice Glasses Salamence and CBtar perhaps it is finally Regirock's time to shine.
Registeel @ Leftovers
Nature: Impish (+Def -SAtk)
Trait: Clear Body
EVs: 252 HP / 4Atk / 252 Def
-Ice Punch
-Thunder Wave
-Arm Hammer
-Rest / Explosion
CBtar's Crunch does 16.4% - 19.5% to Registeel, while Stone Edge does 20.3% - 23.9% to it. CB Earthquake is an obvious problem for Registeel, as it does 54.9% - 64.5% to Registeel (ouch), but outside that and a possible Focus Punch (82.1% - 96.4%) Registeel can wall CBtar rather well while 2HKOing with Arm Hammer. On the special attacks end AG Salamence's Meteoric Swarm does 32.4% - 38.1% damage and Dragon Pulse does a meager 20.8% - 24.7%. It can 2HKO that Salamence with Ice Punch to boot. CB Salamence with Earthquake makes Registeel sad, though. Has obvious problems with Choice Glasses Starmie since it doesn't resist anything outside of Ice Beam or the possible Grass Rope.

Registeel (Steel)
Base Stats: 80 HP / 75 Atk / 150 Def / 75 SAtk / 150 SDef / 50 Spd
Ability: Clear Body
Notable Physical Movepool
Iron Head
Superpower
Arm Hammer
Focus Punch
Brick Break
Explosion
Aerial Ace
Shadow Claw
Rock Slide
Seismic Toss (Emerald Tutor)
Thunderpunch (Emerald Tutor)
Ice Punch (Emerald Tutor)
Notable Special Movepool
Luster Cannon
Focus Bomb
Charge Beam
Thunderbolt
Thunder
Notable Support Movepool
Thunder Wave
Stealth Rock
Psych Up
Safeguard
Registeel got the short end of the Registick for the most part, but due to the advent of Choice Glasses Salamence and CBtar perhaps it is finally Regirock's time to shine.
Registeel @ Leftovers
Nature: Impish (+Def -SAtk)
Trait: Clear Body
EVs: 252 HP / 4Atk / 252 Def
-Ice Punch
-Thunder Wave
-Arm Hammer
-Rest / Explosion
CBtar's Crunch does 16.4% - 19.5% to Registeel, while Stone Edge does 20.3% - 23.9% to it. CB Earthquake is an obvious problem for Registeel, as it does 54.9% - 64.5% to Registeel (ouch), but outside that and a possible Focus Punch (82.1% - 96.4%) Registeel can wall CBtar rather well while 2HKOing with Arm Hammer. On the special attacks end AG Salamence's Meteoric Swarm does 32.4% - 38.1% damage and Dragon Pulse does a meager 20.8% - 24.7%. It can 2HKO that Salamence with Ice Punch to boot. CB Salamence with Earthquake makes Registeel sad, though. Has obvious problems with Choice Glasses Starmie since it doesn't resist anything outside of Ice Beam or the possible Grass Rope.