Just a note, LO mixed Aegislash can run Head Smash for Mandibuzz even without SD and win with rocks
4 Atk Life Orb Aegislash-Blade Head Smash vs. 248 HP / 136+ Def Mandibuzz: 307-361 (72.5 - 85.3%) -- 75% chance to OHKO after Stealth Rock
Which is fairly possible considering Aegislash spinblocks, beats most other defoggers, and Mandibuzz is a Defogger herself.
So Head Smash beats Mandibuzz, not SD + Head Smash explicitly.
Also, Hippowdon really needs to be healthy to check Aegislash, considering it's one of the few things Aegislash still outspeeds with a Quiet nature
252+ SpA Aegislash-Blade Shadow Ball vs. 252 HP / 112 SpD Hippowdon: 181-214 (43 - 50.9%) -- 4.3% chance to 2HKO after Stealth Rock and Leftovers recovery
Hippowdon with around 10% prior damage is taking a risk at that point, and this is itemless.
Mandibuzz and Hippowdon's synergy also leaves a serious hole for Special Ice Attacks, which is an issue because some Aegislash run HP Ice for Gliscor
252+ SpA Aegislash-Blade Hidden Power Ice vs. 252 HP / 112 SpD Hippowdon: 182-216 (43.3 - 51.4%) -- 6.6% chance to 2HKO after Stealth Rock and Leftovers recovery
Or by just running a good Special Attacking partner with Ice coverage, like this guy
252+ SpA Life Orb Landorus Hidden Power Ice vs. 248 HP / 108 SpD Mandibuzz: 161-190 (38 - 44.9%) -- 62.5% chance to 2HKO after Stealth Rock and Leftovers recovery
252+ SpA Life Orb Sheer Force Landorus Earth Power vs. 252 HP / 112 SpD Hippowdon: 285-335 (67.8 - 79.7%) -- guaranteed 2HKO after Stealth Rock and Leftovers recovery
As noted, the only things most Aegislash sets outright need are King's Shield and Shadow ball, so freeing a moveslot for one or even both of those is still possible.
Clerics can cure off the SubToxic's status, but Clerics tend to sink momentum even by Stall standards, and giving momentum to Aegislash is a huge issue in and of itself.
no, man, it might run cb thunder fang for your azumarill xD
"oh but you're having to use 2 mons solely to counter aegi!" saying that is actually ignoring the great defensive synergy between mandibuzz and hippowdon. you can argue subtoxic beats those 2, but since they're usually ran with cleric support...
So you're running 2 decisively defensive Pokemon to counter Aegislash, plus a Cleric if you really want to beat SubToxic to. I'd personally think needing HALF OF MY TEAM to cover one Pokemon primarily might just seem a bit excessive, especially when covering that mon is locking me into Defensive Balance/Stall because of their playstyle.
Regardless, SD Aegi isn't as viable as the Crumbler set. The 17% usage backs up my claim. Also Aegi needs to actually get an SD off and can still get burned or outspeed by a variety of pokes that it usually counters (Willo Mew, Willo Rotom, Willo Garde, Scald Psychics like Starmie and Slowbro, Heatwave Zapdos, etc).
The SD set is less common than the Crumbler set maybe, but not sure I'd call it less viable. SD + 3 attacks does have a more lategame role, and while not necessarily less effective, it's not as linear or easy to use as Crumbler, so people who are spamming the Ladder with HO to get Reqs will probably use Crumbler more because it's not complicated in how you employ it for a team.
4LO lacks viability because the person using it still knows he doesn't have KS. It's easy to say 4LO is strong as an outside perspective because it gives Aegi a variety of moves to counter every poke. If you actually use 4LO in game vs someone, it's much harder. You need to predict and it can get very risky. People will still be afraid of KS sure, but you'll also be afraid because you don't have it. There's risk on both sides, but I'd argue there's much bigger risk on you losing Aegi for no reason.
I can make the opposite argument that the opponent not knowing about a lack of KS still can work in Aegislash's favor. Say the opponent makes a move on the assumption you do have King's Shield, like launching a Physical attack against Blade forme. Why do they immediately know "he has no King's Shield" rather than "he didn't expect me to call a King's Shield bluff." The opponent is still predicting as if you have King's Shield until you unveil all 4 attacks. The Aegislash user is playing prediction still, but he only has to worry about being prepared for either "the King's Shield reaction" and the "non-KS" reaction from the opponent, so they have a much smaller number of options to weigh.
Prepare for Crumbler and work around the other sets (which consist of less than 20% of the Aegis based on usage). There's always going to be something your team isn't prepared for. Stop acting like preparing for crumbler Aegi doesn't give you an edge against the other sets. It does, and you can work around them.
Preparing for Crumbler doesn't give you an edge over the other sets because many of those other sets are specifically meant to let Aegislash get around answers to the Crumbler set. SubToxic was created specifically because Aegislash retained his powerful Shadow Balls and could still get around things like Mandibuzz and Chesnaught, the common answers to Crumbler. Being prepared for Crumbler doesn't make me prepared for SubToxic: worst case scenario, it makes me weak to SubToxic.
Aegislash can be a decent revenge killer but you'd be doing yourself a disservice by making it one. There are plenty of revenge killers in the game (M-Lop, Lando-I, MAlt, etc) that do a much better job than Aegislash does. Even if aegi is fast Dance, it's still losing to a variety of pokes it would otherwise beat, such a willowispers (Mew, Rotom, Garde), taunters (Gyara, Talonflame), and scalders.
Also in your scenario you ignore the fact that constantly switching allows hazards like SR and spikes to ruin your opponent. 4LO isn't viable for many reasons, this being one of them. If I'm switching something into Aegi, it's probably something that can tank it + heal off the damage, or tank/check it and deal a move that Aegi not a switchin you try to make can deal with (i.e knock off).
Fast SD Aegislash is not a Revenge Killer anyway. It's a late game cleaner, so that's the role you need to find competition for if you want to convince me it's not worth using in that role.
Late game cleaner also entails a number of things eliminated or weakened. Of your WoW users, Rotom-W is prone to being worn down as a pivot with no recovery, I legitimately don't remember where Mew was in the last Aegislash meta, and Gardevoir is not usually going to run WoW since losing Focus Blast leaves it beaten by Heatran, but dropping Shadow Ball leaves it beaten easy by any other of the "more viable" Aegislash sets like Crumbler.
How many mons are able to stomach a LO Base 150 Mon's neutral (at best) STAB attack? Bisharp is the only Knock Off user that can use Pursuit as well, so Aegislash doesn't fear any other user too heavily. Because in a lot of cases Knock Off can be used to switch in your Mega from any other users of the move such as:
-1 252+ Atk Mega Scizor Knock Off vs. 0 HP / 4 Def Gyarados: 70-83 (21.1 - 25%) -- 0% chance to 3HKO after Stealth Rock
Zard-X or Y
252+ Atk Mega Scizor Knock Off vs. 0 HP / 4 Def Charizard: 106-125 (35.6 - 42%) -- guaranteed 3HKO
252+ Atk Mega Scizor Knock Off vs. 0 HP / 0 Def Scizor: 87-103 (30.9 - 36.6%) -- 64.2% chance to 3HKO
252+ Atk Mega Scizor Knock Off vs. 232 HP / 0 Def Venusaur: 102-120 (28.4 - 33.4%) -- 0% chance to 3HKO
As well as other mons that take the move well such as
- Poisoned Gliscor
to name a few.
And the mon has to be able to tank the hit, heal itself, and make sure you still get momentum back from whatever switches in to take Aegislash's place.
Usange =/= viability, but usage is a strong indicator for viability. In fact, it's the strongest indicator we have. The fact that Aegi runs HS ~5% does mean that many people don't find it viable enough to run at all. Are we really going to ban something because of that one time you lost to an HS Aegi. It will rarely, if ever happen.
Also your Hippodown argument defeats itself. "Hippodown was UU but A by viability." That's why it advanced and went OU. Head Smash usage isn't increasing at all, and probably never will.
My Hippowdon argument was made with the premise that he was A ranks for almost 15 months, but only just moved up to OU proper THIS month. And Head Smash is a niche option, but it's a niche option that gets the results it's intended to when they run it. And besides that, we have had one month for a sample size for the time Aegislash has been back in OU. Usage does not indicate viability as strongly as you entail because despite Hippowdon being a threat everyone agreed was viable in the metagame, he took a long time for his usage to reflect that. Head Smash is a niche option, and while a noteworthy niche, by nature that means it's not going to find use a huge number of Aegislash's sets.
We're not banning it over the one time someone lost to HS Aegislash. HS is just another asset that, while not as heavily, still warrants being weighed in preparing for Aegislash as a Pokemon. And the sum of Aegislash's assets make it a burdensome Pokemon to prepare a team for.
If you want to convince me otherwise, you need to explain to me what factors in the metagame make Aegislash ineffective in those roles and makes his remaining sets manageable without being a significant constraint on teambuilding.
Here's the thing, there are mons that can counter every aegi set except SD. If you can counter all non-SD sets and pack a solid SD aegi counter, then you have aegi countered every time, just swap in the non-SD counter when aegi comes in, and if he tries to SD in your face, swap to your SD counter.
It's worth noting that if mandi survives the head smash on the switch, it can actually stall it out with roost spam. So mandi can actually beat SD sets with full defense investment(barring SR). Mixed lure sets also fail to break mandi.
4 Atk Life Orb Aegislash-Blade Head Smash vs. 248 HP / 252+ Def Mandibuzz: 278-330 (65.7 - 78%) -- guaranteed 2HKO after Leftovers recovery
252 Atk Life Orb Aegislash-Blade Head Smash vs. 248 HP / 252+ Def Mandibuzz: 330-390 (78 - 92.1%) -- guaranteed 2HKO after Leftovers recovery
252 Atk Life Orb Aegislash-Blade Shadow Sneak vs. 248 HP / 252+ Def Mandibuzz: 32-39 (7.5 - 9.2%) -- possibly the worst move ever
That's still 2 slots just to prepare for Aegislash itself to be fair, even if that does cover the sword. The SD counter then has to be kept healthy until it actually boosts (which by nature of that set tends to be late game when things are worn down by teammates or hazards).
And Mandibuzz not having prior damage or hazard damage, while possible, is not as likely to pan out in practice since that either also entails Mandibuzz having never taken damage before Aegislash came out with Head Smash. Shadow ball, while tanked, still can shave that health down over time since Mandibuzz becomes exploitable by Roosting, and Aegislash can still carry Flash Cannon
252+ SpA Life Orb Aegislash-Blade Shadow Ball vs. 248 HP / 4 SpD Mandibuzz: 108-127 (25.5 - 30%) -- 0.2% chance to 4HKO after Leftovers recovery
252+ SpA Life Orb Aegislash-Blade Flash Cannon vs. 248 HP / 4 SpD Mandibuzz: 216-255 (51 - 60.2%) -- 88.3% chance to 2HKO after Leftovers recovery
This also makes Mandibuzz pressured to stay at high health if it checks anything else on the team. And avoiding hazard damage means Mandibuzz isn't going to work well as a Defogger.
4 Atk Life Orb Aegislash-Blade Head Smash vs. 248 HP / 252+ Def Mandibuzz: 278-330 (65.7 - 78%) -- 25% chance to OHKO after Stealth Rock
4 Atk Life Orb Aegislash-Blade Head Smash vs. 248 HP / 252+ Def Mandibuzz: 278-330 (65.7 - 78%) -- guaranteed OHKO after Stealth Rock (at 90% pre-SR damage)
And even then, is running one of the small pool of checks really a sign of a healthy metagame around Aegislash? Kangaskhan strong-armed Tank Chomp-esque sets, Sableye and RH Ferrothorns onto teams, Genesect and Mawile pushed a lot of Heatran usage. Aegislash is obviously not
anywhere near this level of absurdity, but if the effect of this centralization is needing two teamslots with very specific Pokemon to be considered adequately prepared for Aegislash, I think that's an unhealthy alternative to the match-up issue Aegislash is meant to mitigate.