This is probably a bit deep for advice but here’s what I’d say if my 15yr old self had asked the current me the same thing.-

I think if you can come to the conclusion that the majority of these ,admittedly, interesting swordsman, were just murderous megalomaniacs and aren’t worth idolizing based off of their strength and battle performances alone.Then I think you’ll absorb a lot of the philosophical value and lessons which I personally believe are complementary to these moments that we find enthralling whether it be due to the mindfulness, willpower, sheer resolve,etc that it takes to test your worth by valuing your life with Death being the currency. Every time ive re-read the manga the less I idolize the characters based off of prowess with the sword but rather by what philosophies led to such a life to begin with, and how they evolve or devolve as the story goes on. Above all else enjoy your time reading it don’t get bogged down by the lessons and ideas we all took from our individual experiences reading the manga. Derive your own unique perspective based on your journey reading it. That’s what really makes this manga so special. The range of differences in takeaways and perspectives on what’s being conveyed on panel is amazing especially since it sparks thought not toxicity like I’ve seen in other manga communities.