Alright I think I'll lump my fair share of experience in here.
HIDDEN POWER CHARIZARD-MEGA-Y
With how strong ZardY is, people are finding more ways to stuff it's usually set of moves. Two such methods are Rain, pioneered by Pelipper, and Moltres, and it just so happens that they both have 4x weaknesses. So...
Charizard-Mega-Y (M) @ Charizardite Y
Ability: Blaze
Tera Type: Fire
EVs: 252 SpA / 4 SpD / 252 Spe
Timid Nature
IVs: 0 Atk
- Weather Ball
- Solar Beam
- Scorching Sands
- Hidden Power [Electric] / Hidden Power [Rock]
That's right, we bust out Hidden Power. HP Electric OHKOs standard Pelipper as they usually don't invest in Special Defense, while HP Rock does a sizable chunk to Moltres while also threatening Volcarona and opposing Charizard-Y. The greatest thing is, both Rain and teams with Moltres often don't have another Pokemon that can withstand Zardy (especially Rain, who is helpless after Pelipper gets nuked by HP Electric), so that just nets a guaranteed win unless they also have some weird tech. In fact, so many of my opponents know this that they just forfeit after Hidden Power is revealed.
IMPRISON TRICK ROOM JIRACHI
This is a Doubles specific tech. Jirachi is a really good support Pokemon, and with Trick Room being one of the two dominant playstyles in NDDOU, it just so happens that Imprison Trick Room causes a lot of issues for them.
Jirachi @ Leftovers
Ability: Serene Grace
Tera Type: Water
EVs: 252 HP / 224 SpD / 32 Spe
Sassy Nature
- Imprison
- Trick Room
- Follow Me
- U-turn
Standard Jirachi shenanigans with Follow Me and U-Turn to bring in teammates safely, plus Tera Water for a standard defensive typing. Even though Imprison and Trick Room may seem like two dead moveslots outside of Trick Room matchups, it can actually provide a bit of help elsewhere. Imprison can also block Follow Me from the likes of other Jirachi and Ogerpon forms, while Trick Room can be used as a last-ditch effort against something like Dragon Dance MegaMence that has already set up. The point is though, Jirachi bulky, Jirachi block Trick Room, no Trick Room, happy, opponent no happy.