Jeremy in the 'jeremy monster story' might be a young adventurer. He could be someone who is curious and that's why he gets into a situation with a monster. For example, if the story is set in a magical land, Jeremy might be exploring and accidentally disturbs a monster's lair.
Geralt ends up with Yennefer. Their relationship is complex and filled with passion. They have a deep connection that has been through many trials and tribulations throughout the story. They care for each other deeply despite their differences and the various challenges they face in the world of the Witcher. It's a relationship that is central to much of the story's emotional depth.