Wish Mandibuzz: Hmm...kinda on the fence on this one. Agreeing wholeheartedly that Mandibuzz deserves some support moves, however with Wish she still faces some serious competition from other Wish users. Alomomola generally outclasses her as a pure Wishpasser due to Regenerator, while Clefable has a gigantic movepool to fill in even more roles (Rocks, Heal Bell, etc). That said, her excellent mixed defenses and unique set of resistances could carve her just enough of a niche to get RU usage. She does much better with things like Sceptile and Typhlosion who can break Clefable with Focus Blast.
Solid Rock Rhydon: I feel like this guy should definitely have it since he really needs Head Smash for Rock Head to be useful. Anyway, I do think there will be some disappointment as always with Solid Rock, the list of moves he can now tank is incredible. Examples include Banded Cinccino Bullet Seed, LO Accelgor Giga Drain, Tank Tangrowth Giga Drain, and Defensive Slowking Scald, while avoiding 2HKOs from things like Qwilfish Waterfall, Scarf Mesprit Ice Beam, Lead Accelgor Focus Blast, and physical Entei HP Grass. Definitely a useful ability and bound to make him top 10.
Unnerve like a special Intimidate: Turtleye kinda hit the nail on the head with the viable users things. That said, Coil Arbok now looks much interesting, being able to boost his Defense while retaining decent special bulk. But the big winner in my eyes is Aerodactyl. With Unnerve, he can now add some bulk to his Choice Band set, or add more immediate bulk to any set lacking Double-Edge. He also gains an option for a Bulky Hone Claws set with Roost/Taunt and EdgeQuake to set up on big threats like Moltres, though he's still vulnerable to revenge killing by his usual counters.
Finally, one of my own:
What if Drapion had Moxie?
Drapion was a good Pokemon once, but now it's seen as too weak for an great offensive set while not quite enough bulk for a great defensive set. So I feel like Drapion deserves a boost, although I kinda struggled to find just one thing that would help him that still sorta kinda fit with flavor. Moxie was my best guess (his Dex entry states "it takes pride in its strength", so something like Moxie, or its Japanese name Overconfidence, seemed to kinda fit), and it somewhat alleviates the offensive problem, as once he KOs a weakened Pokemon, it becomes harder for defensive Pokemon to stomach his blows. A Scarf set becomes somewhat viable as a cleaner, since 95 Speed is enough to outspeed many speedy threats in RU (Scarf Emboar, Rotom-C, and Rotom-N, or Aerodactyl and Accelgor). However, early on it is still difficult for him to get through defensive Pokemon like Alomomola and Ferroseed (they need +4 for a 2HKO), and if he uses Swords Dance to speed up the process he still struggles with many of the aforementioned revenge killers who can hit him super-effectively or on his weaker defensive side. SubSalac is the last option I see, getting the Speed of a Scarf while maintaining the power of SD, but then he's much weaker to basically all priority. So would Moxie help Drapion? Can any 1 thing help Drapion?