So I was messing around with the Hax+Conk core, and I came to the conclusion that paralysis really helps here. Not only does it stop Scarf users like Hydreigon from shitting all over Hax, it lets Conk use another move besides Mach Punch against faster threats like Infernape and non-scarf Keldeo. The fastest user of T-Wave in UU is Klefki, and with a great defensive typing and access to spikes, it can really support Hax and Conk, due to the switches they force.
Here's the set I've been using:
Klefki @ Leftovers
Ability: Prankster
EVs: 252 HP / 212 Def / 44 Spe
Bold Nature
- Spikes
- Thunder Wave
- Play Rough/Dazzling Gleam
- Foul Play/Magnet Rise/Flash Cannon
The set is fairly straight forward; Spikes are a great form of residual damage, wearing heavily on checks to Hax or Conk such as Amoonguss and Megatoise, T-Wave is to stop scarfers or other DDers like Gatr, Craw, or other Hax's not holding lum berry, Play Rough is to smack Dark types that are immune to Prankster, like Megapedo and Megabsol not carrying Fire moves. I usually run Foul Play in the last slot to discourage setup, but Magnet Rise seems like a fun option to setup on Hippowdown or Gliscor. I put in 44 Spe EVs to outspeed uninvested base 80's like Goodra, Togekiss and Mandibuzz (although looking back i really don't know why as Kiss and Mandibuzz don't do much to Klefki anyway, and Goodra is a rare sight in UU anyway lmao). The EVs are pretty customizable, i've even run attack EVs to catch stuff like Megabsol off guard. I use Def instead of SpD as I find myself switching into more physical attacks, but like I said, the EVs are pretty customizable.
EDIT: Looking at the core again, i see it's pretty weak to fairies even tho Conk can lure and KO, so i changed the possible moveset to include Flash Cannon and Dazzling Gleam.