There is an entire branch of role-playing games these days that argue that balancing is a pointless endeavour, so just make it clear to the players that so and so is gonna kill them if they ain't careful and let them figure it out. It's called Old School Renaissance and as a GM, I absolutely love that approach.

Dark Souls is exactly that. You wanna go through that boneyard? The skeletons that one shot you and keep respawning don't intimidate you? Then fair fucks to you and onward to glory. Otherwise better take the other path or come up with a stratagem.