I don't really like Naive on Hydreigon as it hinders him a bit while checking Houndoom (which is really not common atm because infernape and bliss but w/e) so Hasty and Timid are the preferred natures in my opinion.
+1 252+ Atk Life Orb Honchkrow Sucker Punch vs. 0 HP / 0- Def Hydreigon: 165-195 (50.7 - 60%) -- guaranteed 2HKO
The main reason I don't want to go with Hasty is because it makes it a tad easier for this sucker to take you out. It's happened one too many times, while I don't really have a problem with M-Hound
Anyway, I infer that it's up to preference.
Dark Pulse is really useful for its neutral coverage and to revenge kill Victini, Alakazam, Jirachi, Chandelure, Metagross and a ton of other Pokemon Hydreigon checks whitout the special attack drop and Hydreigon only needs Draco-U-Turn-Dark Pulse-Fire Blast anyway, especially on Choice Scarf sets.
Well, I thought Flamethrower was enough for Jirachi and Metagross but I see your point:
252 SpA Hydreigon Dark Pulse vs. 252 HP / 252 SpD Jirachi: 204-240 (50.4 - 59.4%) -- 75.4% chance to 2HKO after Leftovers recovery
252 SpA Hydreigon Fire Blast vs. 252 HP / 252 SpD Jirachi: 184-218 (45.5 - 53.9%) -- 2% chance to 2HKO after Leftovers recovery
252 SpA Hydreigon Flamethrower vs. 252 HP / 252 SpD Jirachi: 152-180 (37.6 - 44.5%) -- guaranteed 3HKO after Leftovers recovery
Alakazam still threatens with Focus Blast, I wouldn't stay in on it unless I was scarfed and locked to Dark pulse (in which case Zam won't switch in anyway). Fun Fact (just found out):
252 SpA Alakazam Focus Blast vs. 0 HP / 4- SpD Hydreigon: 326-384 (100.3 - 118.1%) -- guaranteed OHKO
252 SpA Alakazam Focus Blast vs. 0 HP / 4 SpD Hydreigon: 294-346 (90.4 - 106.4%) -- 37.5% chance to OHKO
I think I'm going with Timid after all on Scarf Hydreigon.
Hydreigon can also easily switch into and threaten Slowbro especially if it doesn't have Thunder Wave so Aerodactyl and almost anything walled by it is a good partner. The LO set is good with anything that appreciates Florges removed (Iron Tail 2HKOes cleanly) so Mienshao, non-CB-Heracross, Mega Blastoise and a miriad of special attackers are good.
Slowbro may also carry Ice Beam, so there's that too. I always think twice before switching in.
As for "Iron Tail 2HKOes Florges cleanly": I like to not use that word for moves with 85% and less acc. Iron Tail 2HKOes *if it hits twice* which will happen ~56% of the time. Not good enough, especially if the other pokemon can OHKO you with
Fairy Wind Moonblast. Of course Flash Cannon is a joke vs Florges so I thing I'll just U-turn out of there into Roserade or something.
Slowbro (who in UU outclasses Slowking in almost every way)
Yes I know, but WHY? On paper, the only difference is a bit extra Def vs a bit extra SDef. Same Abilities, movepool, typing, everything. Is this pokemon that much more reliant on physical rather than special bulk?
And could someone please elaborate on some common/effective Slowbro(/king) sets?
Sorry for rambling on for too much, thanks again for replying.