Silksong Steel Soul without save quitting has been achieved.
I cannot count how many times I lost to that challenge, but now I've finally done it.
Here are some tips for Steel Soul without savescumming (100% run):
1. Do not rush. I had to show immense patience myself (yeah, rushing killed me countless times). Do you think you can beat the High Hall gauntlet with just one Needle upgrade and no tools? Forget about it! Take your time—unless you’re so practiced from your failures that you can reach Swift Steps in 20 minutes; in that case, go for it, because it makes movement way easier.
1.5. It's good to have all the abilities. Just remember to always play it safe.
2. Have a parallel save. Whenever I reached a boss that I had only beaten during my first playthrough and couldn't remember what strategy to use, I would create a normal save to practice fighting them there (I didn't fully gear up on that save, which made the practice runs harder, but it meant that doing it on my Steel Soul save—where I had most of the items—was much easier).
3. Plasmium. Get it as soon as you can and replenish your supplies.
4. Do everything you can before Act 3. You definitely don't want to fight Void-infused bosses who can deal way more damage, do you?
5. Avoid the enemies in the Abyss (the big, spitting ones). They only appear in two places—in one, you can easily pass underneath them, and in the other, right over them.
6. Nyleth doesn't exist, don't risk fighting Seth.
7. Only do what's necessary for the 100% run. Ignore mementos and extra boss fights like Tormented Trobbio.
That’s all I can think of. If you have any questions, I’ll try my best to answer them.
