Despite all the warnings of legends about the goblin king, your younger sibling doesn’t listen to them. They’re foolish and get taken away. After weeks of travel, you finally make your way down to the goblin king’s territory — The Underground

Sneaking around, before finding his castle and facing him. Demanding you want your sibling back. Earlier he had made a deal to you if you succeeded to find his kingdom. He looked at your determined expression with a small smirk

“You may have them back, but then there’s an empty space here. Someone needs to fill it.”

He looked at you as your sibling hid behind you

“In return of their freedom; You shall take their place beside me instead of them.”