Rotom-Frost @ Choice Scarf 
/ Icium Z
Ability: Levitate
EVs: 252 SpA / 4 SpD / 252 Spe
Timid Nature
IVs: 0 Atk
- Volt Switch
- Blizzard
- Trick / Pain Split
- Thunderbolt
Rotom-Frost is an incredibly threatening pivot in ZU, using Volt Switch to gain momentum while threatening defensive switches with its STAB combination, but suffers defensively from a few issues. Among those issues are a weakness to common priority moves and a weakness to Fire type moves.

Grumpig @ Mago Berry
Ability: Thick Fat
EVs: 252 HP / 80 Def / 176 Spe
Timid Nature
IVs: 0 Atk
- Psychic
- Focus Blast / Toxic
- Substitute
- Recycle
Grumpig steps in and covers some of Rotom-Frost's weaknesses, taking on Fighting type priority users handily through its Psychic typing while using its Thick Fat ability and natural special bulk to take on the other STAB of those Pokemon with relative ease. Grumpig can also break a couple of Pokemon such as Muk for Rotom-Frost.
---Teambuilding Weaknesses---
This core greatly appreciates a partner that brings sturdy physical bulk, as the two together fail to offer much in terms of physical bulk against strong attackers. These two also need to be wary of Silvally-Dark, which can pick off a weakened Rotom-Frost and Pursuit trap Grumpig, as well as other Pursuit trappers such as Bouffalant.