Steal what he came for.

Sébastien has not expected her to reply to his message so soon but he was happy to see it. 

(Alright be careful) This was the first time Ellen had replied in three words. From the writing, Sébastien could guess that she might have been nervous after seeing his message.

Just as he thought to comfort her that he will be fine. New words appeared in the blank space.

(you promised to be careful and not allow anything to harm you. You are not allowed to get injured. Those soldiers from the other kingdoms can not be trusted. There is no guarantee that those kings did not plan to use the knife in their hands to deal with you).

Sébastien paused after reading this message, of course, he knew that the four great kings would have dared to play such tricks if he has not made them swear an oath of death. 

The reason why he decided to let them become a. Independent kingdom after the war was to be able to hold their loyalty.