Here are my early impressions of Gen 8 DUU (I'm adding more as I encounter and use more mons):
The tier is severely lacking in speed control. As Deathman said, Noivern is the only viable tailwind setter at the moment, barring maybe Mandibuzz. I think that sticky web (on Araquanid) could be the speed control of choice for a lot of teams , but to be honest, with all the trick room flying around, it may not see much use.
Trick room is extremely popular, with setters including Runerigus (which is overrated), Aromatisse, Trevenant, Malamar, and Indeedee.
Runerigus is overrated, and is lacking in both bulk and power. Do not use it.
Aromatisse is an attractive option for trick room teams due to Aroma Veil and provides excellent bulk and decent offensive power.
Trevenant is a decent option for setting and abusing trick room due to its good sustain and bulk but is highly vulnerable to burns due to its reliance on Horn Leech. Requires proper cleric support or a burn absorbing mon.
Noivern sees use as a tailwind setter and generally annoying fast mon.
Cinderace is, in my opinion, overrated, but its offensive potential cannot be underestimated. Its powerful U-turns crush the tier's Psychic and Grass types, and its Pyro Balls destroy most neutral hits. Nevertheless, it struggles to find room to enter the field due to its nonexistent bulk. It must watch out for Golidopod's Aqua Jet, Barraskewda's Liquidation, and any of the tier's numerous Rock Slides.
Hitmontop seems to me to be the best intimidator right now, but in a tier as slow and bulky as this one, I am doubting its usefulness.
Goodra seems to be doing its best to imitate an immovable object.
Mew is very flexible. It can run a set with rocks and spikes, or a swords dance set, or a fast support set with will o wisp. If there is a hole on your team, chances are, Mew can fill it.
Aurora veil Vanilluxe could be promising.
Mudsdale is powerful but relies on stamina boosts to boost its body press damage, and with the abundance of ghost types in the tier, struggles a bit. In addition, it can only come in safely late game after its checks have been dealt with, and Milotic especially crushes it.
Milotic has proven itself to be an incredibly hard to break wall, and by far the best haze user in the tier. Marvel Scale is preferred over Competitive, due to there being literally one moderately viable Intimidator in the tier and it not seeing much use.
I like Umbreon as a support mon with snarl, helping hand, and foul play. However, there is an abundance of strong fighting type moves in the tier, notably Machamp's Dynamic Punch, Mew and Malamar's Superpower, Cinderace's High Jump Kick, and Reuniclus's Focus Blast. Might be better once the meta settles down.
Malamar is a decent trick room attacker, but is crushed by the various powerful U-turns in the tier, so it requires a thorough knowledge of the tier to play well.
Clefable is also popular but seems rather mediocre at the moment, at least until setup becomes popular.
Araquanid seems at the moment to be a highly potent dynamax user, as it is one of the hardest hitters in the tier and is immune to Mew's will o wisp. In addition, it is the best sticky web setter in the tier.
Golisopod shows potential as a hit and run mon and its aqua jets hit a significant portion of the metagame very hard, but it requires good predictions and proper team support.
Hydreigon will probably fill the same role it did last generation; that of an intermediate, powerful attacker. Eject pack seems fine for now but I think that life orb or specs will prove to be better. It finds itself unable to nuke many prominent threats without a boosting item, but it can freely spam Draco Meteor thanks to the lack of viable fairy types in the tier.
Silvally has proved to be fairly powerful with a simple swords dance set. I personally run Silvally-normal with a lum berry, multi-attack, parting shot, and swords dance. However, it has a bad tendency to get outsped and ohko'd. After a swords dance, however, it becomes a premier threat.
The combo of Indeedee and Hawlucha is quite scary, as Hawlucha outspeeds every single mon in the tier with the unburden boost and Indeedee hits surprisingly hard with its life orb psychics.
Weezing-Galar is a decent choice due to Misty Surge negating the abundance of status in the tier. It does struggle to deal meaningful damage though, and its lacking bulk warrants extreme caution when getting it in.
Cursola is an extremely scary Trick Room sweeper, but its terrible physical bulk makes it vulnerable to every remotely strong physical move in the tier, especially Araquanid's Liquidation.
Barraskewda can outspeed the entire tier, even max speed Cinderace, with an adamant nature, and therefore has a good niche as a powerful choice banded or life orb attacker.
Tsareena is quite powerful but has a tendency to simply lose to faster threats, especially Cinderace. If played carefully, it can be a bulky monster. I prefer to run it with a choice scarf to patch up its speed issue.
Reuniclus finds a strong niche as a powerful special attacker, especially with the lack of strong special walls and dark types within the tier. It needs to run Colbur Berry so as to not get ohko'd by any strong Knock Off. It needs to set up substitutes on switches whenever possible, because while it threatens nearly the entire tier offensively, it struggles against many of the powerful Ghost-type mons, notable Gengar and Calm Mind variants of Trevenant.
Greedent will be very easy to deal with for any experienced player, but it nevertheless warrants caution when used alongside a redirector, due to its potential to sweep after a Belly Drum under Trick Room.
Togetic is the most popular redirector at the moment due to its bulk with eviolite. However, its bulk is quite middling and its damage output is lacking, so it will likely end up being a single use trick.
Azumarill
Kommo-o
Ludicolo
Ninetales
Scizor
Thundurus-Incarnate
Venusaur
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NEW -> Tier 5
NEW -> Tier 2
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