The Impossible Boy (HTTYD)

After being stolen from Berk as a mere baby by Toothless, Hiccup embarks on a harrowing adventure defeating dragon hunters, meeting new friends, and making discoveries about himself. Hiccup lives with Toothless on their own private island for 10 years and create a dragon haven filled with rescued dragons. During that time, Hiccup endures a new... development.

But, as always, peace is not everlasting. He is captured by Alvin and trained to fight. A form of hypnosis forces him to attack dragons and help the Outcasts in their fight. Spurred by the monotonous conflict with Berk, Alvin sends his new recruit to handle it - without Toothless. As Hiccup fights his own battles on Berk, Toothless must find his partner in crime before it is too late.

Author's Note: I am in AP English and simp for Grammarly, so it will not be crap, I promise. Please free to make suggestions/requests and constructive criticism.