The fon slot seal was originally developed to close only the external fon slots--but recent advances had it able to close off internal fon slots as well, making it all the more deadly. Only a few, highly elite fonists have ever survived the effects of a fon slot seal, and the seal itself can take several months, even years, to undo, as it is like a lock with a code that changes periodically.
大概是小说中的一段,少数像杰德那样的精英谱术士才有可能慢慢解开封印术。