Agreed very much with the above. I think people seem to be having gripe with this thing because it's not well equipped to handle offence due to mediocre, if not outright bad speed and poor defences, but that's completely missing the point of this thing, it's a through-and-through wallbreaker designed to square off against defensive fat-mons and crack them. Of course fancy Z-Move variants and Scarf sets have their viability but as far as I can tell that puts it on the same plate as Hoopa in that yeah now it hits fast and hard as well and it's all very nice, but it's the most mediocre set it can have since it doesn't make the fullest use of its best qualities (being its monstrous offences) and also falls short to other potential Scarfers you could be running. It's disappointing that it doesn't have a base 110 speed to match with its SpA, but if it did it would've gotten the hammer by now. So what I'm puking out in this massive paragraph is that Tail Glow + 3 attacks is pretty much the best way to go with this thing, giving you the best of its available coverage and make the most of its raw power. It's also not a bad idea to run a Tapu Koko or a Thundy alongside it if you really do want an offence-breaking Electric type. I've heard people say, and I can agree, that Tapu Koko makes a great partner for Xurk, being able to manage faster things and also setting up terrain for Xurk as well to boost a strong hit for a while, of course that's not a long-term benefit to Xurk but it is really effective for helping to break something you need broken. Thundy can also pair well having immunity to Ground so you don't have to worry about shared weakness, and T-Wave support against some threats could make Xurk's job easier against some speedier mons without having to rely on on a Z-move and sacrifice your coverage or TG.
A set like this is what's been helping me out:
Xurkitree @ Electrium Z
Ability: Beast Boost
EVs: 4 Def / 252 SpA / 252 Spe
Modest Nature
IVs: 1 Atk / 30 SpA / 30 SpD
- Thunderbolt
- Energy Ball
- Hidden Power [Ground]
- Tail Glow
Standard TG with a few differences. Since I'm going with the above and have a Koko with me with HP Ice coverage to support me against Landos, Gliscs, Chomps and such, I'm running HP Ground since Alolan Marowak is a very common switch-in for Xurk, more so than the aforementioned Grounds who fear the HP Ice, it can also hit Heatrans for what it's worth. Gigavolt Havoc also adds a boost to muscle through some other fat fucks that would otherwise be a pain to deal with like Mega Venu, Ferro, Chansey, and such, after a TG with that pulled on them it's pretty much a wall down. I also don't see the need for Timid since even Modest outspeeds any defensive sets I can think of off the top of my head and Modest does give you the edge in some cases (example being a +3 Gigavolt Havoc is a guaranteed OHKO against standard defensive Mega Venu from Modest), it even outspeeds tank-Chomp at modest by a touch unless they've started running more speed now. Maybe I'm being too tunnel-vision with this thing but from the perspective of wall-breaking alone Modest makes the cut.
I'll cap this shit off because it's long and boring, but I'll also disagree with the statement that this thing needs a ban. No. This thing's movepool is ok, but far from having masses of options that make it impossible to predict or counter. It's primary niche is wall-breaking and sure you can slap a Scarf on it but even then it's outsped by a lot of fast-mons and being locked into an Electric move really has its obvious drawbacks, particularly with Duggy being a thing. Even as a wallbreaker it lacks the options Hoopa-U has which pretty much broke the back of any defensive team with its available options of breaking sets and coverage. It's good, but let's not get carried away.