Naruto would be extremely enraged. He would vow to rescue Sakura no matter what. He would immediately start gathering his friends and form a rescue team. Sasuke, on the other hand, might initially seem more reserved but would also be determined to get Sakura back. He would use his Sharingan skills to track Madara.
Sukuna does die in the manga. The way it happens is quite dramatic and ties in with many other elements of the story, adding depth and tension to the overall narrative.
Harry would be on guard at first. He has faced many dark threats in his life, and Madara would seem like another one. But as he gets to know Madara better, he might see some similarities in their struggles. Dumbledore would likely be very interested in Madara. He would try to understand Madara's motives and see if he could be an ally or a threat to the wizarding world. Dumbledore would be cautious but also open - minded in dealing with this new and strange character.
The Leaf Village would be in chaos at first. Hinata is an important member of the Hyuga clan, and her kidnapping would not be taken lightly. The Hokage would immediately call for an emergency meeting. They would start by sending out search teams, likely led by some of their best shinobi like Kakashi or Shikamaru, who are known for their intelligence and combat skills.
No. Ryomen Sukuna is a fictional character from Japanese mythology and modern manga/anime. He doesn't have a basis in a true historical event or person.
Nope. Ryomen Sukuna has no basis in reality. It's a product of the creative minds of the writers and illustrators who designed a captivating fictional character for the enjoyment of the audience.