Picking the single strongest ninja in 'Naruto' is addictive to argue about, and I love how messy it is. If I zoom out and judge purely by raw, universe-scale power, Kaguya sits at the top: she literally birthed chakra on Earth, rewrites reality with dimensions, and can create whole worlds with ease. Her abilities dwarf normal shinobi techniques; she’s not just a better ninja, she’s a near-cosmic force. That said, calling her the best fighter is complicated because strategy, stamina, and teamwork matter hugely in the series.
If I narrow it to playable, repeatedly impactful fighters across the timeline, Naruto and Sasuke stand out. Naruto’s Kurama, Six Paths energy, and mastery of varied battlefields make him extremely versatile, while Sasuke’s Rinnegan grants space-time and ocular prowess that can erase threats or subvert attacks. Madara and Hashirama are also contenders for their era-defining feats: Madara as the Ideal Uchiha power fantasy and Hashirama’s near-mythic chakra and Wood Style that defined power balance in war.
So my take? Kaguya is the absolute apex in existential scale, but for a living, tactical champion who shapes the world repeatedly, Naruto and Sasuke feel like the strongest balanced pair. I admit I’m still team-Naruto on feelings alone.