money12wolf, Avalugg already gets Iron Head and Rock Slide.
Onto my submissions, though! Here's to praying at least Drapion or Aggron makes it in, and that we can one day actually play with these updated mons.
Pokemon: Aggron
Type: Steel/Rock
Old Stats: 70 / 110 / 180 / 60 / 60 / 50 (530 BST)
New Stats: 85 (+15) / 130 (+20) / 180 / 40 (-20) / 70 (+10) / 65 (+15) (570 BST)
Abilities: Sturdy / Rock Head / Sand Stream (HA)
New Moves: Accelerock, Shift Gear, Shore Up
Justification:
The Swiss-Army-Knife syndrome returns to Aggron's doorstep, granting upon him buffs that could probably make him cry (if gods could cry.) The addition of Sand Stream gives him a viable supporting third ability to contest the defensive Sturdy and offensive Rock Head for slots, giving him amazing team support alongside Sand Rush threats (see below). A revised stat spread also supports more roles Aggron can do. Increased HP and Special Defense allow him to be played tanker with Sand Stream, while a buffed Attack stat makes all-out offensive sets stronger in combination with a better, although slightly so, Speed stat.
Speaking of Speed, most Steels nowadays have a way to catch up with the rest of the game due to a generally low base Speed, whether it be a broken as hell Mega (cough Lucario cough Metagross), Priority, or a boosting move. While his Mega actually makes him slower in this form, he has the other two laid out for him. Accelerock is amazing for nailing common Ice, Fire, and Flying-types before they can act, hitting for STAB and allowing Curse sets to suffer less at the hands of faster Will-o-Wispers. Shift Gear gives Sturdy and Rock Head sets a breath of fresh air, allowing Aggron to boost its Attack and Speed at the same time. With a base speed of 65, many common threats are outsped, but many fast Scarfers around base ~100 Speed will be even still be faster. Shore Up helps Sand Stream Aggron's normally terrible survivability due to its typing, boosts its weak Special Defense, and gives Curse sets a breath of fresh air for Mega Aggron as well.
Pokemon: Drapion
Type: Steel/Poison
Old Stats: 70 / 90 / 110 / 60 / 75 / 95 (500 BST)
New Stats: 90 (+20) / 125 (+35) / 115 (+5) / 40 (-20) / 95 (+20) / 105 (+10) 570 BST)
Abilities: Sand Rush / Tough Claws / Corrosion (HA)
New Moves: Iron Head, Bullet Punch, Stone Edge
Justification:
Most Pokemon with a Poison/Steel typing you'd imagine would either be defensive, carrying that nice Filter or Levitate to make it much more useful through its dual Immunities and set of resistances. Not this Drapion, who stakes his territory in the desert - and sure knows his way around sand. Sand Rush is the best ability he has, allowing him to become a pseudo-Excadrill, carrying Swords Dance or Acupressure faster than any other Pokemon and being capable of nuking threats off the face of the planet before they can react. Iron Head and Stone Edge are most notably new additions to this playstyle, where you have the coverage, alongside the Elemental Fangs, to take on nearly any adversary.
Past that, Tough Claws helps with Poison Jab, Iron Head, Bullet Punch (also a new addition), the elemental Fangs, and Crunch's damage output, and Corrosion allows Toxic sets to hit Pokemon Drapion struggles with, like Toxapex, Celesteela, and Skarmory. It's Stat Spread hasn't changed too much, with every stat bar Attack and Special Attack getting small bonuses, whereas his Attack was largely buffed, and his Special Attack was dropped even further, which it never used regardless.
Pokemon: Bronzong
Type: Steel
Old Stats: 67 / 89 / 116 / 79 / 116 / 33 (500 BST)
New Stats: 80 (+13) / 80 (-9) / 145 (+29) / 100 (+21) / 145 (+29) / 20 (-13) (570 BST)
Abilities: Filter / Magnet Pull / Berserk (HA)
New Moves: Ice Beam, Earth Power, Recover
Justification:
Bronzong becomes a more reasonable offensive threat, while retaining what makes Bronzong, well, Bronzong. Physically offensively Bronzong's a bit worse, but gains a noticeable buff to its Special Attack. Defenses are also a lot bigger, same but lesser so to HP, and it's even slower for Trick Room teams. Filter works as a pseudo-Levitate/Heatproof, doing a bit of what both do in addition to reducing its new Fighting weakness. Magnet Pull can trap some of the premier Steel-types, including itself, Scizor-Mega, other Magnezone via access to Earth Power, and others.
The main treat comes with the new moves and access to Berserk. With a huge HP, Defense, and Special Defense stat, access to Recover and Calm Mind, Bronzong can slowly start to steamroll out of control, completely tanking through teams. While Filter may seem significantly better for this role due to the fact things like reworked Beartic, Primeape, Hariyama, and even the new Farfetch'd exist, Berserk allows you to continuously gain power boosts as you recover HP, making opponents who can't deal over 50% damage to the incredible 80/145/145 defenses just a bonus to your stats. Criticals and Defense-targeting moves are the bane of it, but Iron Defense can remedy the latter while good RNG can prevent the former. Ice Beam allows it to nail things like Garchomp, Landorus-Therian, and Zygarde with Filter or even otherwise due to such a massive defensive stat spread, while Earth Power helps it hit tanky Electrics as well as kill most Steels without having to rely on Hidden Power Fire.