Tips for Beating Mr. Stunlock
Well there’s a trait you can pick at game start to make you immune to sealed.
If you don’t want to restart there’s a legendary inner manual you can get from reading the bottom book on the top section when reading books at the shifa temple that makes you immune to most status effects including sealed.
You have to read another book to learn a language in a different section.
Update: Read Sanskrit dictionary and Vairocana Solar Sutra (Sanskrit) from shifa temple library.