Nice core GrimoireGod! Specially Defensive Air Slash Pelipper is really good with Pilo and I think should even be the standard set.
Lapras @ Expert Belt
Ability: Water Absorb
EVs: 120 HP / 252 SpA / 136 Spe
Modest Nature
- Hydro Pump
- Ice Beam
- Freeze Dry
- Surf
Lapras is a really interesting pokemon for its ability to destroy balanced cores such as these.
It easily switches in on Pelipper's Scald, Pelipper's Air Slash, and Piloswine's Icicle Spear/Ice Shard and hits both super-effectively. It even avoids the 2HKO from Pilo's Earthquake if rocks aren't on the field, which is incredible. I chose Expert Belt to bluff the Specs.
Calcs:
252+ SpA Expert Belt Lapras Hydro Pump vs. 252 HP / 0 SpD Eviolite Piloswine: 360-425 (89.1 - 105.1%) -- 31.3% chance to OHKO
252+ Atk Piloswine Earthquake vs. 120 HP / 0 Def Lapras: 180-213 (41.7 - 49.4%) -- guaranteed 3HKO
252+ SpA Expert Belt Lapras Freeze-Dry vs. 248 HP / 252+ SpD Pelipper: 408-490 (126.3 - 151.7%) -- guaranteed OHKO
0 SpA Pelipper Air Slash vs. 120 HP / 0 SpD Lapras: 75-88 (17.4 - 20.4%) -- possible 5HKO

Lapras @ Expert Belt
Ability: Water Absorb
EVs: 120 HP / 252 SpA / 136 Spe
Modest Nature
- Hydro Pump
- Ice Beam
- Freeze Dry
- Surf
Lapras is a really interesting pokemon for its ability to destroy balanced cores such as these.
It easily switches in on Pelipper's Scald, Pelipper's Air Slash, and Piloswine's Icicle Spear/Ice Shard and hits both super-effectively. It even avoids the 2HKO from Pilo's Earthquake if rocks aren't on the field, which is incredible. I chose Expert Belt to bluff the Specs.
Calcs:
252+ SpA Expert Belt Lapras Hydro Pump vs. 252 HP / 0 SpD Eviolite Piloswine: 360-425 (89.1 - 105.1%) -- 31.3% chance to OHKO
252+ Atk Piloswine Earthquake vs. 120 HP / 0 Def Lapras: 180-213 (41.7 - 49.4%) -- guaranteed 3HKO
252+ SpA Expert Belt Lapras Freeze-Dry vs. 248 HP / 252+ SpD Pelipper: 408-490 (126.3 - 151.7%) -- guaranteed OHKO
0 SpA Pelipper Air Slash vs. 120 HP / 0 SpD Lapras: 75-88 (17.4 - 20.4%) -- possible 5HKO