So even if, logically, the Deoxys-S on my opponent's team is best suited as a dual screener, and it turns out to be an LO set that screws me over, that's my fault?
You're missing the point. It doesn't have to be Rayquaza, it can be any uber, because they all have some weaknesses and some checks. If your only logic is "x is checked by y and z therefore not broken" then you have to unban literally every banned Pokemon because that applies to all of them.
If one had a better choice than sending in their Bisharp that's OHKOed by Deo's fighting move of choice and hoping to win the Sucker Punch/Pursuit guessing game, I think one would go to it.
I guess all those successful offensive teams that are destroyed by Deoxys-S are just built poorly. This is the 3rd generation in a row LO Deo is terrorizing offensive teams for the same reasons it always has and you somehow want to blame it on bad teambuilding?
It is the definition of a 50/50 because there is no "right" move. If they Superpower you on the attempted Pursuit, Bisharp's dead and you're probably getting swept since you most likely didn't have a better answer if you had to send that dude in on Deo. If they switch on your Sucker Punch, they come back in later, probably get another kill, and then you do this over again. Logically you could say "well he wants to come in again for another KO so I'll Pursuit" but what if he sees through that and kills you? If anything I'd say it's even in the Deo user's favor if you want to go that way because at least if you Sucker Punch you guarantee you won't lose right then and there, making switching a little safer, but even that can go the other way. 50/50.
Those stats aren't the most impressive but it's using high powered moves with a Life Orb and it's got excellent super effective coverage so while "lack of power" is a nice argument in theory, in practice it just doesn't work like that. Similarly, hazards and screens may not have immediate effects on the battle but you are severely downplaying how important they can be especially when they're set up so easily.
The Beginner's guide to countering Deoxys-Speed -
Do you want to counter it? Use a Slowbro!
20 Atk Life Orb Deoxys-S Knock Off (97.5 BP) vs. 252 HP / 252+ Def Slowbro: 120-143 (30.4 - 36.2%) -- guaranteed 3HKO
236 SpA Life Orb Deoxys-S Psycho Boost vs. 252 HP / 0 SpD Assault Vest Slowbro: 95-113 (24.1 - 28.6%) -- 97.7% chance to 4HKO
20 Atk Life Orb Deoxys-S Superpower vs. 252 HP / 252+ Def Slowbro: 36-44 (9.1 - 11.1%) -- possible 9HKO
236 SpA Life Orb Deoxys-S Ice Beam vs. 252 HP / 0 SpD Assault Vest Slowbro: 40-48 (10.1 - 12.1%) -- possible 9HKO
The mixed cleaner set Deoxys cannot touch AV Slowbro, and AV Slowbro can also Regenerator off the damage when Deo switches, while chipping away with 3HKO Scald, when it can.
4 SpA Slowbro Scald vs. 0 HP / 4 SpD Deoxys-S: 94-112 (39 - 46.4%) -- guaranteed 3HKO
Another Pokemon it can't touch is Ferrothorn, its also great to bulk many hits from many HO Pokemon.
236 SpA Life Orb Deoxys-S Psycho Boost vs. 252 HP / 0 SpD Ferrothorn: 104-123 (29.5 - 34.9%) -- 100% chance to 4HKO after Leftovers recovery
20 Atk Life Orb Deoxys-S Knock Off (97.5 BP) vs. 252 HP / 252+ Def Ferrothorn: 53-64 (15 - 18.1%) -- possible 8HKO after Leftovers recovery
20 Atk Life Orb Deoxys-S Superpower vs. 252 HP / 252+ Def Ferrothorn: 133-156 (37.7 - 44.3%) -- guaranteed 3HKO after Leftovers recovery
236 SpA Life Orb Deoxys-S Ice Beam vs. 252 HP / 0 SpD Ferrothorn: 90-107 (25.5 - 30.3%) -- 0.5% chance to 4HKO after Leftovers recovery
Ferrothorn is easily able to tank a hit, albeit not as well as Slowbro, from a Deoxys-Speed, and throw back a huge 2HKO Gyro Ball, EVEN IF Ferrothorn has to switch into an attack, it can handle it.
4 Atk Ferrothorn Gyro Ball (150 BP) vs. 0 HP / 0- Def Deoxys-S: 187-222 (77.5 - 92.1%) -- guaranteed 2HKO
Another good response to Deoxys-Speed is Mega-Mawile.
236 SpA Life Orb Deoxys-S Psycho Boost vs. 252 HP / 4 SpD Mega Mawile: 122-144 (40.1 - 47.3%) -- guaranteed 3HKO
20 Atk Life Orb Deoxys-S Knock Off vs. 252 HP / 0 Def Mega Mawile: 25-30 (8.2 - 9.8%) -- possibly the worst move ever
20 Atk Life Orb Deoxys-S Superpower vs. 252 HP / 0 Def Mega Mawile: 91-108 (29.9 - 35.5%) -- 26.3% chance to 3HKO
236 SpA Life Orb Deoxys-S Ice Beam vs. 252 HP / 4 SpD Mega Mawile: 52-62 (17.1 - 20.3%) -- possible 5HKO
236 SpA Life Orb Deoxys-S Psycho Boost vs. 252 HP / 4 SpD Mawile: 190-224 (62.5 - 73.6%) -- guaranteed 2HKO
Although Psycho Boost can 2HKO, Mawile can mega-evolve and slam Deoxys for an OHKO.
252+ Atk Huge Power Mega Mawile Sucker Punch vs. 0 HP / 0- Def Deoxys-S: 400-472 (165.9 - 195.8%) -- guaranteed OHKO
You know who else can beat Deoxys-Speed? Both M-Scizor/Scizor -
236 SpA Life Orb Deoxys-S Psycho Boost vs. 252 HP / 4 SpD Mega Scizor: 117-139 (34 - 40.4%) -- guaranteed 3HKO
20 Atk Life Orb Deoxys-S Knock Off vs. 252 HP / 0 Def Mega Scizor: 44-53 (12.7 - 15.4%) -- possible 7HKO
20 Atk Life Orb Deoxys-S Superpower vs. 252 HP / 0 Def Mega Scizor: 82-97 (23.8 - 28.1%) -- 95% chance to 4HKO
236 SpA Life Orb Deoxys-S Ice Beam vs. 252 HP / 4 SpD Mega Scizor: 51-60 (14.8 - 17.4%) -- possible 6HKO
236 SpA Life Orb Deoxys-S Psycho Boost vs. 252 HP / 4 SpD Scizor: 142-168 (41.2 - 48.8%) -- guaranteed 3HKO
20 Atk Life Orb Deoxys-S Knock Off vs. 252 HP / 0 Def Scizor: 60-71 (17.4 - 20.6%) -- possible 5HKO
20 Atk Life Orb Deoxys-S Superpower vs. 252 HP / 0 Def Scizor: 110-130 (31.9 - 37.7%) -- 94.7% chance to 3HKO
236 SpA Life Orb Deoxys-S Ice Beam vs. 252 HP / 4 SpD Scizor: 61-71 (17.7 - 20.6%) -- possible 5HKO
And they both can OHKO it!
252+ Atk Scizor U-turn vs. 0 HP / 0- Def Deoxys-S: 306-362 (126.9 - 150.2%) -- guaranteed OHKO
252+ Atk Mega Scizor U-turn vs. 0 HP / 0- Def Deoxys-S: 338-402 (140.2 - 166.8%) -- guaranteed OHKO
How about Aegislash?
20 Atk Life Orb Deoxys-S Knock Off (97.5 BP) vs. 252 HP / 0 Def Aegislash-Shield: 127-151 (39.1 - 46.6%) -- guaranteed 3HKO after Leftovers recovery
236 SpA Life Orb Deoxys-S Psycho Boost vs. 252 HP / 0 SpD Aegislash-Shield: 82-97 (25.3 - 29.9%) -- 0.1% chance to 4HKO after Leftovers recovery
Deoxys-S Superpower vs. Aegislash-Shield: 0-0 (0 - 0%) -- aim for the horn next time
236 SpA Life Orb Deoxys-S Ice Beam vs. 252 HP / 0 SpD Aegislash-Shield: 36-43 (11.1 - 13.2%) -- possibly the worst move ever
Able to take even a Knock Off twice, and throw back an OHKO. And if you've weakened it a little, revenging it is no sweat.
252+ SpA Aegislash-Blade Shadow Ball vs. 0 HP / 4 SpD Deoxys-S: 348-410 (144.3 - 170.1%) -- guaranteed OHKO
4 Atk Aegislash-Blade Shadow Sneak vs. 0 HP / 0- Def Deoxys-S: 152-180 (63 - 74.6%) -- guaranteed 2HKO
Hey thats only 5 Pokemon, so I have to have one of these five on my team to beat a Deoxys-Speed, still overcentralising Jaffa Ball!
CB Dragonite can do it as well! -
252+ Atk Choice Band Dragonite Extreme Speed vs. 0 HP / 0- Def Deoxys-S: 179-211 (74.2 - 87.5%) -- guaranteed 2HKO
236 SpA Life Orb Deoxys-S Ice Beam vs. 4 HP / 0 SpD Multiscale Dragonite: 205-242 (63.2 - 74.6%) -- guaranteed 2HKO
A QD Volcarona can do it to!
+2 252 SpA Volcarona Bug Buzz vs. 0 HP / 4 SpD Deoxys-S: 660-776 (273.8 - 321.9%) -- guaranteed OHKO
236 SpA Life Orb Deoxys-S Psycho Boost vs. 4 HP / 0 SpD Volcarona: 227-269 (72.7 - 86.2%) -- guaranteed 2HKO after Leftovers recovery
EDIT: SO CAN BISHARP if... its already in-
252+ Atk Life Orb Bisharp Sucker Punch vs. 0 HP / 0- Def Deoxys-S: 439-523 (182.1 - 217%) -- guaranteed OHKO
But I bet the argument is gonna come up - Pokemon can still have many checks and still be broken. Slowbro is a counter. Shove it in everytime you want it to wall Deoxys-Speed. Ferrothorn and Aegislash and Scizor and Mega-Mawile can do the job as well. Shove in an Excadrilll against hazard-setter, use one of the many checks to OHKO it when using screens setter. Also it appears your argument still stands regardless of how many checks you can list, it doesn't affect brokenness. THERE IS A COUNTER, which I am lead to believe is different from a check. But then you'll say so I have to use a Slowbro if I want to counter Deoxys! Thats not the only way! Exploit solo-type and shit-defenses with any of your priority (ideally Sucker Punch)
users or your bulkier attackers, watch the success.