Some advices:
Ferrothorn:
Use Relaxed > Impish so that Gyro Ball is stronger. I would also throw out dat Power Whip and add Thunder wave. The reasons:
- Power Whip is not super great ; it has a lackluster accuracy and Ferro doesn't hit so hard.
- Thunder Wave will ruin the plethora of Scarf users.
Jellicent
Use that on Jellicent:
Jellicent (M) @ Absorb Bulb
Trait: Water Absorb
EVs: 252 HP / 220 Def / 32 SAtk / 4 SDef
Calm Nature (+SDef, -Atk)
- Scald
- Recover
- Hex
- Ice Beam
Trachy, I'm looking at you, I stole your set. Pardon me. It's just so great. :)
Ultimate synergism and coverage. Mamoswine is active, it's gonna have hard time against dat Surf, you switch in and not only erase surf, but get a benefit of + in special attack. Scald deals status conditions, precisely Burn, and that's why Hex is getting strengthened. Finally, Ice Beam is a nice coverage, especially against the multitude of Dragons here.
Volcarona
My very strong set:
Volcarona @ Leftovers:
Trait: Flame body
EVs: 252 HP / 204 defense / 52 Speed
Bold nature
- Flamethrower
- Quiver Dance
- Roost
- Bug Buzz
This set is designed for ultimate sweeping and the EV spread lets Volcarona tank some hits. All is about Quiver Dance which boost your Special Force alongside your speed. After 3 ~ 5 Quiver Dance, nothing resist both dual STAB ; Flamethrower and Bug Buzz. Roost is finally here to heal some damage, most notably SR.
Gliscor
Use this:
Gliscor @ Toxic Orb:
Trait: Poison Heal
EVs: 244 HP / 248 Def / 16 Spe
Impish Nature
-Earthquake
-Roost
-Swords Dance
-Fling
This set is quite intriguing:
E-Quake for obvious STAB. Roost may heal off some nasty damage. Swords Dance powers up E-Quake to death. Fling is the only possibility against Flying and Levitating stuff, as your are throwing Toxic Orb meaning you poison the opponent. If this set is not working, then use what you have.
Blissey
Seems fine.
Hitmontop
I would not use this in OU. I would rather use Conkeldurr:
Conkeldurr @ Life Orb:
Trait: Sheer Fore
EV: 252 HP / 252 Atk / 4 Def
Adamant Nature
- Mach Punch
- Ice Punch
- Bulk Up
- ThunderPunch
That thing is beast. Mach Punch is a great finisher on weak or weakened threats. Ice Punch and ThunderPunch abuses the Sheer Orb combo to be ridiculously strong, and finally Bulk Up is Bulk Up, it is making Conkeldurr beast.
Hope this help.