Regieleki + Scarf Xurkitree Electric
Before Eleki is banned I thought it would be cool to explore the limits of just how stupid Electric Terrain can be while Extender is still out. For this I've gone with an offensive partnership of Regieleki and Xurkitree in the mold of the oldstyle DragMag builds.
Between Lightningrod, Motor Drive, and Volt Absorb, the only relevant mons outside of Ground immune to Electric are:
Thundurus-T, Lanturn, Zeraora, and Marowak-Alola, all of which are either themselves Electric or relatively niche mons on their respective types, as Lanturn is generally restricted to stall and Marowak-A is outclassed by Blacephalon. Having lost access to Tail Glow and z-Moves, Xurkitree would appear to have fallen further down the pecking order of Electric's best abusers. However, when placed behind a teammate with greater damage output than Band Dracovish, I believe this tandem should be very fun to abuse in the present shitstorm.