What do you get when you take Thundurus and Tornadus Incarnate forms, stick them in a blender, and inject it into a Weezing? You get this monstrosity of a Pokemon. Granted, on paper it looks like it should be a walking… floating storm seeing as it’s a taiko drum that spews storm clouds, but bear in mind that the thing also has Weezings BST and distribution.
Type-wise, it ditches Poison and picks up Electric/Flying, which is never a bad typing in and of itself since it’s only weak to Rock and Ice and has the ever-useful Ground immunity that most teams seem to love having around.
Ability-wise, it gets Cloud Nine, Amplifier, and Volt Absorb. Of the three, never, never use Cloud Nine if you intend to use this thing seriously. Delta Weezing loves Rain support and almost requires it to be a threat, but that’ll never happen if its mere presence negates weather.
Amplifier boosts Sound-based moves by 50%, and it just so happens to get Boomburst which can effectively function as a third STAB move that ignores Substitute. The problem is that Boomburst is the only move that would warrant taking this ability.
Volt Absorb is more situational and may see more use in double battles, but on the flip side if you don’t plan on running Boomburst having another immunity is never a bad thing, and Weezing can appreciate the occasional free heals. Plus, it’s not reliant on Boomburst either, it just happens to be a good move.
Move-wise, the most prominent ones in its pool are its access to both Hurricane and Thunder, both potent moves that almost make up for the thing’s lackluster Sp. Atk stat. The fact that they provide the dual threat of Confusion and Paralysis (albeit unreliably at just 30% each) just sweetens the deal since one can cripple opponents while attacking, which is something most BP 110 moves can’t offer with any sort of reliability.
Also, this thing comes with Roost. Always good to have recovery.
Item-wise, Choice Specs and four attacking moves is an option to help shore up its lackluster offenses, Life Orb does the same without locking you into an item, Leftovers actually works reasonably well on it due to its bulk as well.
Wet Rock can be good if you want to use Delta Weezing as your rain-setter, but there are better options for that role.
The most obvious moveset happens to be:
Countering this thing isn’t hard though. Defensive options include anything with the Electric type, since they’ll resist both of its STAB moves. Magnezone stands out as not only resisting Hurricane and Thunder, but also resisting Boomburst which might have put a dent in other electric types. Special attacks will also rip right through it, and with its Base 60 speed it’s not hard to outrun either.
In fact, given how its Base Sp. Atk is only 85 and with few to no ways to actually boost it outside of Charge Beam, Weezing will never hit particularly hard and any specially defensive Pokemon in general will be able to handle it, save for things weak to its STAB typing. Boomburst should be watched for, however, as it will hit through Substitute and even though Delta Weezing doesn’t hit particularly hard, a move that’s been boosted up to BP 210 should not be ignored.
Granted, while Thundurus does’t use Flying type moves, it DOES have Prankster to its name in its Incarnate forme, and Zapdos does almost everything Delta Weezing does but better with the exception of Boomburst. Its near-reliance on Rain to hit as hard as possible means that Sun teams will give it trouble since Hurricane and Thunder both get their accuracy cut to 50% in Sun, and I think Hail and Sandstorm will both reduce their effectiveness.
It’s a quirky Pokemon and alright for in-game, especially for dealing with a certain Water-worshipping Cult, but competitive-wise it struggles to find a niche that isn’t already covered by stronger Pokemon.