Natsu is Tsuna's personal Box Weapon, a remodeled Sky Lion equipped with cutting-edge Vongola tech. It's still growing, and the weapon's personality mirrors its master—shifting between a formidable fighter and a nervous, easily startled cub depending on the situation.
Like other Leone di Cielo, Natsu can sync enemies with the battlefield through Sky Flame harmony. But its real standout feature is the ability to transform into the weapons of both Vongola Primo and Tsuna himself via Cambio Forma: a defensive cloak or an offensive gauntlet, plus arm thrusters in its V.V.G. form.
As a small lion cub around 20cm long (tail not included), Natsu packs serious power despite its modest size, boasting an S-rank in raw strength. Speed and intelligence fall to B-rank, while stamina sits at C. Combat-wise, it relies on standard lion tactics—biting, scratching, and lacerating—though it can also unleash a proper Sky roar and purr contentedly when the moment calls for it.
Since both come from the same base Box Animal lineage, Natsu shares some DNA with Xanxus's Bester, though they've developed quite differently. The weapon debuted in the manga at Chapter 240 and anime Episode 167, with its Version X variant arriving later at manga Chapter 328.
Content compiled by AnimeList.moe from publicly available sources.
