Basculin @ Life Orb / Leftovers
Role: NU Wall Breaker
Ability: Adaptability / Mold Breaker
EVs: 248 Atk / 8 Sp. Atk / 252 Speed
Naive Nature (- Sp. Def, + Speed)
- Final Gambit / Superpower
- Waterfall / Aqua Jet
- Hidden Power [Electric] / Ice Beam
Basculin does have a niche as a Stall Breaker. With access to Taunt and Final Gambit, it can easily defeat most walls.
Taunt + Final Gambit is always a nice combo for breaking through walls and works well with Leftovers. The problem is that if it wants to use attacks, the lack in power is considerable. Superpower is a nice alternative to Final Gambit for more coverage and has good power when combined with Life Orb.
Waterfall has great power and STAB. Aqua Jet would work better with Final Gambit because it can revenge kill with Aqua Jet and then take down a bulky wall (that switches in) with Final Gambit.
Hidden Power [Electric] has more situational uses, but it is alot more better with Seismitoad gone. It is meant to nail Water-types like Poliwrath, Samurott, Pelipper, and Prinplup (although you have to be careful around with Lanturn because it might have Volt Absorb). On the other hand, Ice Beam deals with Grass-types, such as Lilligant. Basculin also could work as a lure for physically bulky Water-types because most people are expecting a phsyical sweeper set and Water-types can wall Basculin.
Note: Adaptability should be used with Aqua Jet to boost its power, while Mold Breaker can be used with Hidden Power [Electric] / Waterfall just in case if there is a Water Absorb or a Volt Absorb Lanturn (or any other Pokemon with the same abilities).