Nomming Araquanid to Tier 3 and Porygon2 from Tier 5>3
First of, I would like to state how I've come to these conclusions. I've currently peaked 1807 with 87.2% gxe on the DOU ladder, and I'm still climbing. Both of these above pokemon are in my team, and they perform excellently. This isn't because I use a niche team that caters to their needs, but it's because in my opinion they are heavily underrated pokemon that can peform a variety of roles.
Their matchup against some common tier 1-2 pokemon is at times lacking, which is my justification for tier 3. They however don't belong in tier 4, let alone tier 5, as they are better than the following description of tier 4: "Pokemon which have broad applications on a variety of teams but are simply less effective than the Pokemon in the higher tiers. This also includes Pokemon which, while good, only fit on a specific team style or require heavy support but are still stronger than Pokemon in the tiers below "
Here's why:
Araquanid:
This spider isn't on the rankings at all, which is very suprising to me. This spider has seen huge success in various other Doubles formats, such as Battelspot Doubles and both the VGC 17 and 18 scene. Both of these formats has slight differences, but they also have many similarities. This spider has a wide movepool that allows it excel as an attacker on semi-TR teams. As well as that, it has very respectable bulk and access to a variety of support moves.
Finding an amazing ability in water bubble spidey hits just about everything that is neutral to water for huge damage. See the following:
-1 252+ Atk Water Bubble Araquanid Liquidation vs. 0 HP / 0 Def Landorus-Therian: 300-352 (94 - 110.3%) -- 56.3% chance to OHKO
252+ Atk Water Bubble Araquanid Liquidation vs. 252 HP / 0 Def Incineroar: 444-528 (112.6 - 134%) -- guaranteed OHKO
252+ Atk Water Bubble Araquanid Liquidation vs. 0 HP / 0 Def Metagross: 164-194 (54.4 - 64.4%) -- guaranteed 2HKO
Araquanid gets to wall all Metagross without Thunder Punch (which is a suboptimal move anyway as Stomping Tantrum hits a larger portion of tier 1-2), walls Landorus effectively, and does the same to Incineroar. These are just three common threats, and I could list more. Slap on a z-move and things get even scarier.
252+ Atk Water Bubble Araquanid Hydro Vortex (160 BP) vs. 0 HP / 0 Def Metagross: 306-360 (101.6 - 119.6%) -- guaranteed OHKO
-3 252+ Atk Water Bubble Araquanid Hydro Vortex (160 BP) vs. 0 HP / 0 Def Landorus-Therian: 336-396 (105.3 - 124.1%) -- guaranteed OHKO
You get the picture. To follow up it then also carries bulk allowing it to take vital hits where needed, considering speed investment isn't needed:
252 SpA Tapu Koko Thunderbolt vs. 224 HP / 0 SpD Araquanid in Electric Terrain: 282-332 (84.6 - 99.6%) -- guaranteed 2HKO
252+ Atk Landorus-Therian Rock Slide vs. 224 HP / 100 Def Araquanid: 140-166 (42 - 49.8%) -- guaranteed 3HKO
The list goes on., and the bulk increases with berries etc. Now this is already fair reason to have him in a tier at least, but there's more of course. So far he's already capable of being a reliable switch-in and check to two of the tiers top-threats, alongside hitting everything else for big damage. He get's great support moves on top of this too! Toxic, Wide Guard, Sticky Web, Lunge and Icy Wind can all be viably used depending on a teams needs. Toxic allows you to beat the annoying Volcanion and Gastrodon that would otherwise wall you, and the others aid the rest of the team. This spider is not a one-trick pony, and caters to a variety of needs without all too much required team support. The only things you need to cover are grass types and electrics, but the same could be said for any high-tier water type.
Onwards to Porygon2.
Porygon2:
Why is this Duck in tier 5? It is perhaps one of the bulkiest offensive Trick Room setters in the meta-game and it isn't getting the recognition it deserves. I can't even add many calcs as this duck survives just about everything and it then gets reliable recovery in the form of recover as well! Even if you play badly and let your eviolite get knocked off this duck will still be taking hits most of the meta-game wouldn't be. It's a good switch-in to almost everything, can setup Trick Room, and has some of the best type coverage in the game whilst having a great typing in Normal. This duck has seen huge success in Battlespot Doubles, VGC 17, and it's even considered a better alternative at times to Cresselia in the current VGC 18 scene. I know this, I topped the ladder in 18 last month with a variant of the team I use for DOU (I literally changed one move and recalculated sets). Now to show off it's offensive power, and don't forget it frequently gets a boost from Download:
16+ SpA Porygon2 Ice Beam vs. 0 HP / 4 SpD Landorus-Therian: 360-428 (112.8 - 134.1%) -- guaranteed OHKO
+1 16+ SpA Porygon2 Ice Beam vs. 248 HP / 4 SpD Assault Vest Landorus-Therian: 360-428 (94.4 - 112.3%) -- 68.8% chance to OHKO
+1 16+ SpA Porygon2 Ice Beam vs. 0 HP / 4 SpD Tapu Koko: 142-168 (50.5 - 59.7%) -- guaranteed 2HKO
+1 16+ SpA Porygon2 Ice Beam vs. 92 HP / 0 SpD Zygarde: 472-556 (124.2 - 146.3%) -- guaranteed OHKO
16+ SpA Porygon2 Ice Beam vs. 92 HP / 0 SpD Zygarde: 316-372 (83.1 - 97.8%) -- guaranteed 2HKO
+1 16+ SpA Porygon2 Thunderbolt vs. 252 HP / 28 SpD Tapu Fini: 176-208 (51.1 - 60.4%) -- guaranteed 2HKO
+1 16+ SpA Porygon2 Ice Beam vs. 240 HP / 96 SpD Amoonguss: 242-286 (56.4 - 66.6%) -- guaranteed 2HKO
This duck is scary if it gets the boost, and even without it's threatening large chip damage whilst also boasting huge sustainability, speed control, and support options. Shadow Ball variants can be run. Foul Play can be run. Icy Wind may be a better option. Or perhaps even Toxic. This thing was considered the most splashable mon in VGC 17, and in DOU it can fit onto almost any Semi-TR team ranging from offensive to defensive. It definitely doesn't belong in Tier 5.