Dark_Peace

He had already influenced the world simply by his unique existence. His encounter with Helena was a turning point because he wanted to help her, and in doing so, he made his influence felt like that of a god within Athena's territory. He couldn’t avoid the quest because he was worried about what might happen to Helena after his departure from this world. Without his protection, she would be vulnerable. To ensure her safety, he reached an agreement with Athena, ensuring Helena wouldn’t become a target. She’s just a little girl who reminded him of himself, and it was obvious she needed help. If you read carefully, you’ll notice this. Does a little girl have to scream for help for him to step in? As for the situation feeling forced—he never intended to get involved in this world, but as you’ve seen, he always ends up involved to witness the story’s conclusion before he can leave. His methods depend on what he feels is right for the situation, so I don’t think there’s anything wrong with his actions.

从丧尸宇宙开始的美漫之旅 Author：一杯白开淼

why?

Yep

It's because he discovered the lamp's abilities.

Possibly Hermione, further along in the story.