One manga that could be similar is 'High School DxD'. It features supernatural elements and a focus on a group of students with special powers and their adventures.
The ending of Rosario Vampire manga is quite complex. The main characters face some major challenges and their fates are tied up in a way that leaves readers with a sense of closure but also some room for interpretation.
The Rosario Vampire manga ends with a climactic showdown and resolutions for the main characters. It leaves some room for interpretation but offers a satisfying conclusion to the series.
The Rosario Vampire manga is pretty clean in that aspect. You won't find any nudity. It's all about the supernatural adventures and relationships of the characters.
I don't have the exact figure for how many Rosario Vampire manga books exist. It could be around 10 or more. The series was popular and had multiple installments over time.
Here are some recommendations for vampire novels and comics:
1. My Wonderful Life Author: Nine Egrets Are Not Fragrant
2. Wolf Howls by Nine Knives
3. Dark Night Castle by Juushirou
4. "Kneel and Beg for a Chamber of Hot Blood" Author: Feng Diuzi
5. [BloodXBlood] Author: Monster Boat
6. Vampire Knight
7. The Transformation Story series
8. "Vampire Princess Miyuki"
9. [Masatsuki Tan Yueji]
10. Blood of the Holy Demon
11. Vampire Hunter D
12. " Naturally Bold Vampire Concubine "
13. Vampire Alliance
14. The Cross and the Vampire
15.《crimezone》
16. Blood-increasing Ghost Fruit Forest
17. [The Tale of Crimson Blood]
18. Bats Must Fall in Love, Author: Garnamore
19. Vampire Manual by Yan Liangyu
20. " Sweeping All the Blood Race " Author: Tetrus D
21. My Vampire Faints Blood Author: Three Thousand Dreams
22. [Source Blood] Author: Chu Han Yi Qing
23. Vampire Knight
24. Black Deacon
25. " My Vampire Goddess is unable to sign a contract with anyone."
26. "My deskmate can suck blood."
27. "The Vampire Princess is not to be trifled with."
These works cover vampire novels and comics. You can choose to read them according to your interests.