For some reason or another, Hail had become my favorite weather to use back when it was legal in UU and it was incredibly difficult shifting from UU hail to OU now that Snow Warning is banned in lower tiers. SubSeed Abomasnow is no longer as viable as it was in UU.
From all the experience I had gained using Hail pretty successfully in OU, these are 2 best sets that IMO every Hail team should utilize or at least try out.
Abomasnow (M) @ Expert Belt
Trait: Snow Warning
EVs: 252 Atk / 112 SAtk / 144 Spd
Lonely Nature (+Atk, -Def)
- Wood Hammer
- Ice Shard
- Hidden Power [Fire]
- Earthquake
Expert Belt Abomasnow is by far the best set it can run in OU. Wood Hammer cleanly OHKOes Tyranitar, Ice Shard ruins Landorus, Hidden Power Fire wreaks the common Scizor wanting to switch into your dual STAB. Most Abomasnow run Blizzard instead of EQ, but its because of this reason that EQ is so useful. After seeing HP Fire, everyone immediately dismisses the possibility of EQ and switches in their Heatran only to get taken down by EQ.
EVs listed give Abomasnow the highest possible attack to spam powerful Wood Hammer and Ice Shard while the Speed EVs allow it to outspeed defensive Heatran in case your Abomasnow hasn't lured in it already and killed it. Expert Belt allows it to get all of the important KOs such as killing Ttar with Wood Hammer, Landorus with Ice Shard, Scizor with HP Fire, and Heatran and Magnezone with Earthquake. Speed EVs might catch some defensive TTars and Politoeds off guard and cause them to think that you are Choice Scarf, another great attribute gained from EBelt.
Kyurem @ Leftovers
Trait: Pressure
EVs: 56 HP / 236 SAtk / 216 Spd
Modest Nature (+SAtk, -Atk)
- Substitute
- Dragon Pulse
- Blizzard
- Focus Blast
Sub + 3 Attacks Kyurem has been in my experienced the best Kyurem set by far, setting up on the countless Water-type Pokemon in OU such as Politoed, Rotom-W, or Tentacruel and taking them down swiftly with Dragon Pulse. Most people again will expect Choice Scarf and often switch in death fodder into this, giving it a free Substitute for it to wreak havoc. Even without any offensive item, Kyurem hits incredibly hard capable of even 2HKOing Choice Band Scizor with Focus Blast if it has not fallen down already to lure Abomasnow or other Hail supporters such as Tentacruel and Heatran.
Other Pokemon that greatly support Hail are Tentacruel, Heatran, Deoxys-D, and even Froslass.
Tentacruel and Heatran do their job of walling Scizor while setting up hazards and keeping them off your side. Both Pokemon also help check other weather such as Tentacruel against Rain or Heatran against Sun. Deoxys-D and Froslass are both viable Pokemon for hail as they provide some buffer against Terrakion and set up Spikes for your team. Deoxys-D holds the advantage against Froslass for handling Terrakion and Reuniclus better, but gives up offensive presence, Speed, and ability to Spinblock. Froslass on the other hand does have some tricks up its sleeve such as Destiny Bond and Snow Cloak, making a shaky but decent enough check to Terrakion thanks to being immune to Close Combat and Snow Cloak making Stone Edge extremely inaccurate.
EDIT: Speaking of which this actually reminded me to probably update my OU Hail RMT