I genuinely forgot I had an account because I very rarely hop on these forums but heres a few calcs for you regarding Rotom-W:Also, has anybody tried to use Rotom-W against it? Idk if it would work or not since I haven't tried it myself, but I think it would be a very good check that we know from past gens can potentially do well in OU.
252+ Atk Choice Band Strong Jaw Dracovish Fishious Rend (170 BP) vs. 252 HP / 252+ Def Rotom-Wash: 182-215 (59.8 - 70.7%) -- guaranteed 2HKO after Leftovers recovery
Rotom is 2HKOd so it cannot switch in as the given EV spread makes it slower than Vish.
If we elect to give Rotom the minimum amount of speed EVs to outrun Band Vish (Adamant ofc):
252+ Atk Choice Band Strong Jaw Dracovish Fishious Rend (170 BP) vs. 252 HP / 88+ Def Rotom-Wash: 210-247 (69 - 81.2%) -- guaranteed 2HKO after Leftovers recovery
Yes Rotom does outspeed Dracovish in this instance (168 Speed EVs) and can apply pressure with Will-o-wisp or a predictive Volt Switch, but it now is even poorer at switching in. With prior chip, it can be OHKOd and its only recovery methods are wishpasses, lefties and pain split.
In gen 7 for instance, will-o-wisp PDef rotom only needed to outspeed M-Mawile so it could heaviy invest in defence. Dracovish is quicker and thus Rotom is generally pretty useless against it
I won't get reqs because I'm shocking at gen 8 but for those voting not ban, please do reconsider. Teambuilder options you take for granted in Gen 8 all have underlying tones of trying to prevent vish. With vish gone, teambuilding will open up more.