Short Version:
An overpowered man helps anime and comic characters in exchange for sex.

Long version:
In an unexpected turn of events, an average man meets his demise and finds himself transported to a mysterious new world. Driven by his deepest desires, he yearns to create a group of women who adore him—a Harem. However, he soon discovers a surprising truth: there are no women in this world.

Determined to escape this peculiar realm and protect his virtue, our hero sets out on a challenging journey of self-improvement. Through hard work and unwavering commitment, he attains godlike powers. But even with his newfound abilities, he finds himself confined to a shop within the vast multiverse.

Within the walls of this enigmatic shop, our protagonist faces his true test. As a divine duty, he must assist distressed women from different parts of the multiverse, offering them his strength and guidance. However, the cosmic balance demands a price, and the reward he gets is.... Sex

Throughout his adventure, our hero encounters women from various backgrounds, each with their own unique struggles and stories. As he ventures forth, he becomes deeply involved in their challenges, providing comfort, advice, and protection.

Yet, amid his selfless acts, the man secretly hopes that someday, somehow, his unwavering dedication and kindness will be reciprocated. Will his cherished dream of a Harem come to fruition, or will the universe have different plans for him?

Embark on this captivating journey, where desire, determination, and duty intertwine, showcasing a man's quest for personal fulfillment and the salvation of others.

.....
Worlds:
Oshi no ko
Chainsaw man
Marvel
DC
One piece
Naruto
Attack on Titan
Bleach
Jujutsu Kaisen
One punch man
And more....