I'd say the first book of The Chronicles of Thomas covenant the unbeliever was a wild trip.

In the story, Thomas covenant has leprosy. Due to the leprosy he is numb from the neck down even though he can still walk. He has no sensation when he touches anything and he cannot engage in his chosen profession which is writing. In a fit of pique he rescues a girl that almost gets hit by a car and gets isekaied.

This was written in the late '70s so it was not a common trope at the time.

He arrives in a world of magic on top of a mountain covered in Giant steps, he crawls his way down the mountain and encounters a girl who uses the magic of the land to heal him of his leprosy.

Believing this is all a dream and trying to prove to himself that this is not real, he rapes the girl.

The girls seems very distraught but pulls herself together and guides him into town and that is when he discovers that the white gold wedding ring on his finger is the source of wild magic.

There is a great evil on the land that plans to destroy everything and he is the chosen person, the only person who can stop it.

He has to fight against his disbelief of the world while reconciling his abhorrent actions with his own internal sense of morality in order to have a chance to go home again.

This book spawned a 10 book series covering hundreds of years of history in the land with Thomas Covenant's battle with the forces of evil and the lives of the people of the land resting in his leprosy numbed hands.

It's an amazing work but it is a rough read.