被夺心魔幼虫寄生是怎样一种体验？

What is it like to be parasitized by mind flayer larvae?

In the year 1024 of Galifar, the last war that lasted for a century has ended for 28 years.
The continent of Khorvaire ushered in a period of peace and stability.
The lightning trains that were once used to deploy troops now travel through the wilderness, sending travelers to all parts of the world.
The airships that travel above the clouds are constantly coming and going, bringing the countries on the continent closer together.
The elves of Aerenal huddled on the islands, defending the glory of the past under the guidance of the ancestral spirits.
The monsters of Droum fought each other for the hope of survival.
In the summer of this year, 14-year-old first-level artificer Carl went out to sell the magic props he made.
But when he made a fortune, sat in a carriage, ate hot pot, sang songs, and fantasized about the beautiful future of driving a mecha after saving enough money, he was hijacked by the mind flayer!
When he woke up in the hibernation chamber of the Mind Flayer transformation room, he could only watch a guy with an octopus head put a weird-looking worm tadpole into his eye.
(DND5E rules, the world background is the Last War of Eberron, with appropriate magic changes)