As you really need to learn the mechanics, you should start with a build that let you make a lot of mistakes so you can see what does high damage and what not.

HOW TO:
Focus on being immortal, you can kill him in literally 1ex budget, maybe even less.
Damage will be terrible but at least it will teach you how to do the fight.

I kill him in the first 3 days of the league in 100c budget with zero issues, aw8 on 3ex budget within a week at most, always deathless.

Just build a RF, 9 endurance charges. Instead of RF use SR totem, 6linked on your chest. You can also use searing bond or manually cast SR as a chieftain. Kaom rings, all endurance nodes, high life regen. Hell, even use vitality and but vitality watcher's eye.
Have 100% elemental ailments avoidance (anointment, craft on helmet, craft on gloves, craft on armor), 75 CR, at least 3k regen.
10k hp, about 2mi damage. It's really slow but you can literally afk in his storms and facetank everything. You can even facetank his beam after getting maximum stacks from the spinning red thing.

Is this a good build? No. But it lets you learn the fight.
Again: anything with high regen, 75 chaos res, 9-10 endurance charges and 100% ailments avoidance as you probably can't time anti-shock flasks decently.
Cyclone with nebulochs also works easily (as very fucking slow), molten strike, tectonic.. anything jugg/chieftain/endurance based is VERY forgiving on mistakes... you actually have to try REALLY hard to die (the only way my chieftain can die is if I afk on the middle of the red beams without endurance charges, otherwise I ignore all his skills).

20ex budget you can pick maybe 50 different builds to kill him deathless 100% of the time, insta-phasing EVERYTHING.. but that won't improve your skills at all.

This post was edited by jacob1818 on Jul 22 2020 02:51am

do u have POB for thys immortal madnes ?

It's cutedog but the build is almost the same and it's indeed a nice build.
https://www.youtube.com/watch?v=DT0_kND09RM&t=474s
https://www.youtube.com/watch?v=NV8lYmtZI7c

Just replace gloves, helmet and armor with rares ones enchanted with avoid elemental ailments and anoint crystal skin. It's incredibly hard to die with this setup.

This was my ultra-budge pob (outdated, but just check the basics/principles) fire cyclone jugg, 1k delve viable on 2ex (maybe even 1ex in the current meta) budget (flasks are wrong and some stuff is off, but just the base of the build)
I made this to farm simulacrum 20/20 deathless while grinding 100 safely... but it's just the base: jugg, tanky, endurance, big epeenor, defensive and some damage.
https://pastebin.com/8JiUXcqB

As for the SR totem, no pob sorry, but it's the default RF build with vitality, purity of fire and instead of RF you 6 link SR totem in the armor.

Of course, all those are VERY budget and slow as fuck builds (2ex budget or even less). On the budget you said you have.. you can have something tankier and with literally 10-15x more damage.

Go for anything tectonic/earthshatter/molten strike on a jugg or chieftain, plenty of guides out there. Extremely forgiving.

This post was edited by jacob1818 on Jul 22 2020 04:04am

i was wondering if somone here have something that work already xD i have shadow 96 that will usles after i lvl up jug. Mby i will make rf trickster

try changing your gear and pantheon for sirus on your current chr. You don't have to use the same gear as for mapping...

for shock -> if you don't have immunity then pick reduced shock effectivness pantheon + you can add 25% on boots (mod = reduced Effect of Non-Damaging Ailments on you)
for chaos -> max out resist
for phys -> craft + to min endurance charges on rings and amulet (3 for 12% phys reduction), maybe get aspect of crab (20% phys reduction), etc.

Max chaos res and corrupted blood will help with survival

Experience is what you need, not a better build or higher budget.

If you want a caster then whispering ice ci trivializes everything, literally noob proof.

yea i seen one build "cycone cwc icestorm" was looking realy op

My brother has one, tanks shaper slam with half its es left.
Dps is in the millions too.