QUOTE(polisperic @ Feb 21 2025, 18:13)

I've been trying to get Juggernaut 5 for the first time on an armor piece. After 9 attempts of doing IW on Hell for one piece, I finally got Juggernaut 1 along with Fireproof 1. When I switched to PFUDOR to level up Jugg 1, it instead leveled up Fireproof to 3 and unlocked Elecproof 1. This is so sad.
You should may be try asking that question on Expert thread for best advice for IW?
From my own experience, what I can say is that IW depends mostly on luck... and yeah that sucks.
Specially when IW weapons like looking for Butcher 5 and Fatality 4 or Penetrator 5 and Spellweaver 4.
Ethereal is even more of a nightmare and I think it is torture people IW Rapier to get Demonic or Holy Strike and desired potency of butcher and fatality. Personally, I think that it is insanity...
But as long as you keep doing it and have enough credits to buy amnesia shards, you should be able to get the potency that you are looking for.
Most people may have different ways but for me I try to IW from IW 0 to IW 3.
If I don't get what I want, I use 3 amnesia shards to get back to 0 and repeat.
For example I try and repeat until I get the desired 3 Jugg or 2 Jugg + 1 Elemental potency.
You may also try at IW 0 to IW 4 but then you would have to use 4 amnesia shards to get back to 0.