I'm sure someone as important as Orochi is still alive, and i think he's alive because of either of these two reasons:
1.Orochi's Mythical Zoan ability saved him, i think you should cut off his head at least 8 times to kill him because in his zoan form he has 8 heads. We know every Mythical Zoan is extremely special and has unique abilites such as regeneration, creating shockwaves, air slashes...it would make sense that Orochi's Mythical Zoan has some ability on the same level as the other Mythical Zoans, so it might as well be the ability to have 8 lives, one per head.
2.Fukurokuju saved him by using his special ability which can revive people, i think this may be the case, because Fukurokuju has the same name and design as one of the Seven Lucky Gods in Japanese Mythology, in Japanese Mythology it is said that Fukurokuju is the only member of the Seven Lucky Gods credited with the ability to revive the dead.
1.Orochi's Mythical Zoan ability saved him, i think you should cut off his head at least 8 times to kill him because in his zoan form he has 8 heads. We know every Mythical Zoan is extremely special and has unique abilites such as regeneration, creating shockwaves, air slashes...it would make sense that Orochi's Mythical Zoan has some ability on the same level as the other Mythical Zoans, so it might as well be the ability to have 8 lives, one per head.
2.Fukurokuju saved him by using his special ability which can revive people, i think this may be the case, because Fukurokuju has the same name and design as one of the Seven Lucky Gods in Japanese Mythology, in Japanese Mythology it is said that Fukurokuju is the only member of the Seven Lucky Gods credited with the ability to revive the dead.