Alohan Rai

VS/WC is the hardest moveset and dodging may be required depending on your team.

Legendaries are by no means required, but if you want to make sure you survive all movesets, bring in some of the tankier counters like Tyranitar, Groudon or Rhydon.

EDIT: I found one with S/WC today and soloed him with
L40 SC Gengar
L40 Scizor
L40 Houndoom
L30 Pinsir
L35 Cacturne
L40 Rhydon
Cacturne's first charge move finished off the fight with 20+s remaining.

VS hits like a truck. Because of Tyranitar, you really don't need legendaries. Front load with Tyranitar, or glassier options, and throw in a couple Rhydons at the end.

I'd be happy just to find one. All I'm getting are Meditite and Donphan raids around here :/

Just use Gengar (higher DPS) and Tyranitar (Bite/Crunch). But you will be able to solo defeat Alolan Raichu using 3 Max out Tyranitar only. That's it.

I would like to solo it, unique challenge style preferably.
The problem is, i am not encounter one yet.
All i see is registeel and tier 1-2
Dont know about another area, but many area in my city reporting about drought in T3 and T4 lately...

I did it with
L35 BC T-tar x2
L31 SD-C T-tar
L34 Sp-Shb Gengar
L31 Shc-Slb Gengar (oops, Fortunately it was cloudy)
L31 Ms-Eq Golem
I finished with 3 seconds vs Vs-Wc.
In the future, I'll use shadow ball Gengar ( of course) and trade SD T-tar for Houndoom.

Took me two attempts, but four Tyraniters did it second attempt.

The simulations suggest it is definitely doable with level 30 non-legendaries, but I have yet to actually encounter one.

Depends on weather boost, too. Summer time for me, so super clear. I just took him down with a lvl 28.5 gengar, 2 lvl 32 rhydons (mud slap/earthquake clear boosted), and a level 27.5 houndoom. Think I got the easiest moveset (spark/thunder shock or something), but got him down!

Almost without, though I had 2 Rayquazas to finish the lineup.

I soloed one S/WC Alolan Raichu finishing it literally on the last second with this lineup:
L39 Tyranitar B/SE
L35 Tyranitar SD/SE
L35 Tyranitar SD/SE
L39 Scizor FC/XS
L32 Rayquaza DT/O (finished with the first charge)
L31 Rayquaza DT/O

It happened to be partly cloudy and that's how I explain the use of my SD Tyranitars, though B/C is still much better (have only one B/C that's not been powered up yet, 'cause I don't have enough candies). I'm pretty confident that even if my Cacturne had been in the place of the first Rayquaza, the outcome would have been same.