You might have noticed that Gargatr and Garchados are actually quite similar, as per their standard counterparts. Unfortunately, with a lack of Sheer Force to set them apart, on paper it seems like Garchados is the bulkier, stronger and faster one of the two, but Gargatr has its advantages too. Unlike standard, both pokemon get Swords Dance from Garchomp, but Gargatr still has access to priority Aqua Jet. However, as a Dragon Dancer when three moves are all the coverage you can get, Garchados has advantages due to Intimidate and high special bulk allowing it easy setup opportunities, as well as a nice 101 speed that allows it to speed tie with the likes of Landorus-I in standard and speed creep base 100 mons. It also has higher attack, but what it lacks is high powered coverage outside of Earthquake and Fire Blast. Whilst Gargatr gets Superpower and Ice Punch, Garchados is still stuck with Brick Break and Ice Fang. Gargatr also has a stronger Fire Blast, courtesy of Feraligatr's higher SpA. Gargatr hits harder when at 1/3 health despite having less HP and has a nice evasion boost, to compensate for the lower attack, while Garchados gets his evasion boosted as well but in sand (thereby granting him immunity to sand as well, as per standard Sand Veil), while Intimidate compensates for it's lower physical bulk. Two sides of a coin, really.
A standard Choice Scarf set they can both run:
Gargatr and Garchados @ Choice Scarf
252 Atk 4 SpA or 4 Hp 252 Spe Jolly/Naive
Garchados (M) @ Choice Scarf
Ability: Veil of Intimidation
Shiny: Yes
EVs: 252 Atk / 252 Spe / 4 HP or 4 SpA
Jolly or Naive Nature
- Waterfall
- Dragon Claw
- Earthquake
- Fire Blast / Stone Edge
Gargatr (M) @ Choice Scarf
Ability: Torrent Veil
EVs: 252 Atk / 252 Spe / 4 HP or 4 SpA
Jolly or Naive Nature
- Waterfall
- Dragon Claw
- Superpower / Earthquake
- Ice Punch / Fire Blast
An SD set:
Gargatr (M) @ Life Orb / Leftovers
Ability: Torrent Veil
EVs: 252 Atk / 252 Spe / 4 HP or 252 HP/ 252 Atk / 4 Def
Jolly or Adamant Nature
- Swords Dance
- Aqua Jet
- Waterfall
- Dragon Claw / Dragon Tail
Dragon Tail is listed as an option because with the lack of a speed boost, you're gonna be outsped by a lot of mons with crazy speed in this metagame. If you want to make use of your bulk and run a tank set, go ahead and run SD with Aqua Jet for priority, and Dragon Tail for shuffling.
Garchados excels at Dragon Tail sets too however. It can run a similar set, but it doesn't have Aqua Jet, so Gargatr outclasses it in that regard. However...
Garchados (M) @ Leftovers
Ability: Veil of Intimidation
EVs: 252 HP/ 252 SpD / 4 Def
Careful Nature
- Rest
- Sleep Talk
- Scald
- Dragon Tail
I know using Negative SpA is weird, but Garchados's attack is quite high for Dragon Tail abuse, and it can't really give up bulk on either side too. And well, Scald's only real use is to burn opponents. Gargatr can run a similar set, but lacks Intimidate, has less attack, less mixed bulk and is slower by 1 point (lol). Other than that, it's mostly the same, so Garchados is the superior option.
Garchados @ Rocky Helmet / Leftovers
Ability: Veil of Intimidation
EVs: 252 HP / 164 Def / 76 SpD / 16 Spe
Impish Nature
- Stealth Rock
- Dragon Tail
- Waterfall
- Earthquake
Yeah, I pretty much copied Garchomp's set and replaced Fire Blast with Waterfall. Anyway, Garchados functions quite similarly to Garchomp in that regard, except it loses Rough Skin, but its speed is nearly Identical, you may have to add around 3 more to perform the same speed creeps it did to mons in regular OU (such as outspeeding Neutral Bisharp), but that's subjective really as we don't know what new threats this meta will bring us, so that can be tweaked around a bit. Defensively, it may well have a better typing than Garchomp, with 2x weaknesses to Dragon and Fairy over Garchomp which had the same but with a 4x ice weakness and electric immunity. However, the added bulk should compensate for that.
Last but not least is the standard Dragon Dance set. This is where both mons deviate from Garchomp, as it never had Dragon Dance in the standard meta. Offhand I'd say the superior DD user really depends on what you run as your coverage move. While Gargatr may have Superpower, it's -Atk - Def boost is kind of detrimental to a boosting set, while both can run Brick Break or Earthquake Garchados has higher speed, bulk and attack stats so it's gonna outclass Garchados in that regard. There's always Ice Punch but the damage output from Garchados' Ice Fang makes up for it due to higher attack. However, Gargatr's access to Torrent, while situational, should help it in late game situations, while Garchados' Intimidate lets it have an easier time setting up. It's a matter of preference really.
Garchados @ Leftovers
Ability: Veil of Intimidation
EVs: 88 HP / 192 Atk / 4 Def / 224 Spe
Adamant Nature
- Dragon Dance
- Substitute / Taunt
- Dragon Claw
- Waterfall
Again, I'm taking Gyarados' standard bulk set here, replacing only Bounce with Dragon Claw. If you're feeling lucky, you can run Outrage on this set if you're confident your opponent won't break your sub soon but as always, the claw is more reliable. Pretty straightforward, use sub to avoid status or use your speed to Taunt opponents fast. Again, the speed can be tweaked around when the meta starts.
Garchados @ Life Orb
Ability: Veil of Intimidation
EVs: 4 HP / 252 Atk / 252 Spe
Jolly or Naive Nature
- Dragon Dance
- Dragon Claw
- Waterfall
- Earthquake / Fire Blast / Ice Fang
Simple. Standard DD with two stabs + coverage. Here's what Gargatr can run instead:
Gargatr @ Life Orb
Ability: Veil of Intimidation
EVs: 4 HP / 252 Atk / 252 Spe
Jolly or Naive Nature
- Dragon Dance
- Dragon Claw
- Waterfall
- Earthquake / Fire Blast / Ice Punch / Superpower
Gargatr has the benefit of a stronger Fire Blast and higher BP coverage moves, but it has better things to do. Theoretically, it can run Superpower on a choice band set.
And that's all for now. Gonna make some sprites later...