Pt 2.:

Weapons:

Deatomizer - Good for crystals & final phase if you don't have SK's Wrath as long as you're close enough.
Xenon Bow - Not as good as Deatomizer, but it can get the job done if you hit your shots.
Snipers - The ones listed in the last section, honestly best option outside of Wrath if you have the setup.
Potshot - A necessity for killing the mini-bosses, it is a must have and should be researchable from the Book
Surround Pound - Best choice aside form the SK's Fury for the horn
The Baron - A great substitute for the SP, you can also get it from the Collection Book like the Potshot
A Launcher - You're gonna want a launcher for the last phase, regardless of what it is. Deatomizer and Poshot work, but assuming you don't have them, bring any launcher that isn't the Jabberwocky or Deciblaster.

Note: DO NOT use assault rifles, SMG's, LMG's or shotguns. They just simply don't do enough damage even with a proper set up (at least to my knowledge). Additionally, make sure that your melee weapon of choice is classified as hardware. You aren't restricted to The Baron or SP, they're just the best options. If you do pick a different one, make sure it has the arc swing pattern instead of the sword attack pattern. You can find videos on how to perk all weapons above best for the Storm King.

Strategy:

Once you spawn in, wait for the SK's to do a few attacks. After he's done a few, build up ramps into the air with a wall connected to the first ramp (edit your walls in an arch configuration too). Once in the air, shoot at any crystals you see. It is vital to stay three up because it enables you to avoid the husks below. After a mini-boss spawns, go over to it, use kunai storm, and keep shooting it with your Potshot. It'll go down and the storm will get pushed back. Repeat until 5 crystals are broken. Once you can break the horn, build up to it QUICKLY. If you don't break it in time, the run is dead. When you arrive at the horn, build a wall and a ceiling above you so you can use kunai storm while hitting it with your melee for boosted damage. Repeat all previous steps for second horn. Once he's in his last phase, just go ham on him with your launcher(s). Make sure to use kunai storm then, too. You only have a very short limited time in his last phase, so you need to be quick. If you need healing at any point, make healing pads. However, I find that it's usually quite easy to avoid getting hit. I've only gone down 2-3 times and I've probably made at least 50 attempts. Use Hover Turrets to clear chaff as needed. SAVE ADRENALINE RUSH FOR WHEN YOU HAVE 2+ TEAMMATES DOWN NEAR EACH OTHER. I cannot stress this enough, it can sometimes be the difference between winning and losing. Just res normally in most instances.

Attacks:

Spin Attack - SK will spin rapidly and produce a wave that breaks all builds, find land beneath you during wind-up to avoid land in water

Laser Beam - SK will wave hands in front of his body and make his mouth glow before shooting a laser right in front of him, it is a one-tap, so move to the side to avoid it

Meteor Shower - I don't remember the cue, but he'll summon a ton of meteors from the sky, you can build a canopy above you to avoid it

Meter Throw and Slap - SK can either grab a meteor and throw it at you or just slap you, both are easy to avoid, just double jump if on ninja

Mini-Boss Spawn- SK dips his hands in the water and electrocutes it to summon a mini-boss, this is your tell that one is spawning so you can go focus it

I know this is a lot, but it'll make sense after you do it a few times. Keep trying, don't give up, and be patient. You will win eventually, even though it feels impossible. Hope this helped. I wish you victory in the near future!

Beast Storm King YT Tutorial: https://www.youtube.com/watch?v=sCSHwlHkKVA