Having children earns benefit, start competing for dominance in the world by marrying a wife - Chapter 1408 - 1098: Saint! He has ascended into Saint???

This is a story about the protagonist getting the system, going crazy in the biochemical apocalypse, producing aircraft and tanks, destroying zombies, saving good people and killing bad people.

- Description from novelbuddy

Alex, a veteran soldier, meets an unexpected end on the battlefield. But instead of the final rest, he finds himself reborn into a new world—the magical realm of Harry Potter. Now a young boy, Alex is born into a Muggle family. Yet, despite his non-magical origins, his disciplined training and fierce determination uncover a rare, powerful talent for magic. With a world of spells, wands, and ancient secrets ahead of him, Alex will need every bit of his skill to face the growing darkness led by Voldemort. It’s a time before Harry Potter’s birth; James and Lily Potter are still alive. Join Alex’s journey as he navigates his way through Hogwarts, learns the mysteries of magic, and rises to face the deadly challenges that await, determined to become one of the greatest wizards in history.

The story starts on earth, after some unknown circumstances, the world was suddenly invaded by monsters from other worlds. Many died and even more turned into zombies, starting what many would call 'The apocalypse Era'.

Rin, a normal teenage boy who lost all of his family members was on the verge of falling into despair when a goddess appeared and sent him to another world that was very similar to a game Rin played before the apocalypse.

Her goal from this was simple, trample on all the protagonists and become the strongest creature in that world for a chance to get back what he thought he lost forever.

Accompanied by a cold beauty, both of them embark on a new journey to become stronger, get back to their world and fix everything.