In still in the 'don't really know what I'm doing' category. But guess I'll do some research. Picked up season 9 after a few years off the game. Like season 9 is my first season. I stopped playing before they were added.
on the in game leaderboards you can at least see the skills and all the afixes on their items. that's the most important part, really, and you can consider every item you see mandatory (if you don't have a sparker, ignore the build for now. if you don't have a mandal heal, ignore the build for now, if you don't have the necessary sets, ignore the build for now). As far as gameplay, basically you have elemental exposure to add damage just before you go into archon mode. it's why the build includes all 4 core elements (ice magic missile, arcane black hole, fire archon which becomes lightning thanks to having lightning on your bracers + lightning hydras).
when you're ready to go archon, you use black hole, drop your 2 hydras and go. that'll ensure you get 4 stacks of elemental exposure for immediate maximum damage. then you just jump around trying to aggro as many packs as possible and kill as much as you can. when archon ends, drop hydras, kite and auto until archon is available again.
you'll want as much CDR and AS as reasonably possible.
I'd recommend using Twitch as a resource. lots of very high level Wizards (GR100+ solo) who stream. You can see how the build works generally in terms of playstyle.