So what @Maelstromicus already said is true, except he did one mistake, which is very important, especially for learning that fight.
Each “Shade Of Orobyss” Node spawned in an echo web will be and stay the same, even if you teleport out or die and re-enter it.
If you die, you will lose the Timelinestability gain on that particular node on completion, but the corruption will stay.
But again, the fight itself will be the exact same.
Shade in itself is pretty complex and he has 30 different abilities in total, of which he always received a fixed amount, based on his type and arandom pool of other void abilities.
If you wanna learn more in detail, I actually do have a video about it.
So again: Each Shade Of Orobyss Node has a different randomized skill set, but the same node always stay the same, so if you fail a fight, you can re-enter and learn it again.
This is super usefull, because you can really dive in and learn the fight.
But if you feel like you cannot progress the fight, you can jsut leave it be and try another Shade Of Orobyss, this is also usefull for hardcore, if you see what he does and you feel like you don’t wanna do it, just teleport out.
When you pull the Shade you can already see what type it is and maybe if you have a particular resistance missing or oyu feel uncomfortable iwth a specific skill, just teleport out.
The chance of spawning Shades becoems higher and higher the deeper you go within an echo web and the corruption a Shade gives you will increase.
It is possible to reach Shades that give up to ~20/21 Corruption, but that is very very rare, because most of the time all branches we be blocked before that.
Usually oyu can get to ~15 corruption gain pretty easily, without any major de-tours.