You haven't told the exact format, so I will try to list for as much as I can.
By usage stats:
Little Cup
- Muchlax, Hippopotas and Skorupi with Whirlwind
- Duskull with Haze
- Litten and Shinx with Roar
Therefore, your best bet would be the above Whirlwind users. Stat phazers aren't a big problem in LC, this is evident from the fact that even though Mareanie gets Haze, it has almost no usage. Litten and Shinx are very rarely used, and Duskull's not much good in LC.
ZU
- Garbodor, Cryogonal and Mareanie with Haze
- Hippopotas with Whirlwind
- Rhydon with Roar
Garbodor has the second most highest usage in the tier. However, Haze is carried only 7% of the time, so the same way in LC, stat boost isn't that important to have a phazer for.
PU
- Weezing with Haze and Clear Smog. (Only 5% usage though.)
- Silvally formes with Parting Shot (This probably won't count but there aren't many good ones too...)
Weezing has #4 most usage in this tier, although it carries these moves only 5% of time, meaning stat boosting's not significant here, too.
NU
- Mantine with Haze (a good 33% of the time)
- Gastrodon with Clear Smog (19% of time)
- Mudsdale with Roar (9% of time)
Mantine's getting the most usage of these. Phazers are there due to stat boosting meta more prominent than other lower tiers.
RU
- Milotic with Haze (38%)
- Mantine with Haze (29%)
- Altaria and Politoed with Perish Song (67% and 11% respectively)
Out of these, Milotic has the highest usage and viability thus far.
OU
- Toxapex with Haze (66% of the time)
- Clefable with Unaware (39% of the time)
- Hippowdown with Whirlwind (18% of the time)
- Skarmory with Whirlwind (54% of the time)
- Quagsire with Unaware and Haze (98% and 43% of the time)
Toxapex is the #2 most used Pokemon, which makes it a good choice for a phazer. Clefable and Quagsire can't do anything naturally with their moves, but at least... they ignore the attacker's stat increases/decreases. Hippowdown and Skarmory are good other choices for Whirlwind.
Ubers
- Ho-Oh, Lugia and uh Skarmory... with Whirlwind
- Quagsire with Unaware and Haze
- Lunala with Roar
Ho-Oh is the most used of these. Common set-up sweepers like Xerneas can be handled quite easily through Ho-Oh. Lugia's a tank, and it can also use Whirlwind to phaze out set-up sweepers and other Dragon Dance users. Quagsire is a bit weird choice, but it can handle Dragon Dance Necrozma-Dusk Mane and other users, but remember that Teravolt of Zekrom ignores Unaware. Finally, Lunala is a bit weird choice but since Shadow Shield can't be ignored by Sunsteel Strike or Teravolt, it can pretty easily phaze such users out.
Source
Hope this helps!
