What is Guts' core teaching about suffering?

Not that suffering has meaning — but that you can survive it without that meaning being assigned in advance. Berserk is specifically resistant to the idea that Guts' pain is building toward something clean. He suffers. He continues. The suffering doesn't retroactively become worthwhile; the continuing is worthwhile in itself.

What does Guts model about continuing when there's no good reason to?

Pure momentum. In his worst moments — after the Eclipse, after losing Casca to her damaged mind, after injury after injury — he keeps moving not because hope sustains him but because stopping feels like accepting what should not be accepted. His persistence is irrational by utilitarian measure and entirely human.

What does Guts teach about isolation?

That isolation is costly in ways that accumulate. His post-Eclipse period — fighting alone, rejecting help, using his pain as fuel — is depicted as both understandable and destructive. He's more effective with companions. He's more human with Casca. The lesson isn't that he should have handled it differently; it's that isolation compounds trauma rather than resolving it.

What does Guts model about protecting others despite your own damage?

That damaged people can still protect. He's broken in every measurable way and still keeps Casca alive. The brokenness doesn't disqualify the care. This is one of Berserk's most important and quietly radical claims.

What is the most transferable lesson from Guts?

That the question isn't whether you can survive what happened to you — it's whether you'll keep going anyway. Guts doesn't have good reasons. He has the refusal to stop. In genuine extremity, that refusal is enough. It has to be.