Einz is still practicing to increase his magic power and mana.After he goes out for a walk but when he's walking he sees Rin unconscious, he brings Rin to his kingdom to heal and ask what happened.
When Rin wakes up he feels bad when he sees Einz he don't expect that Einz will save him after the war. Einz ask him what happened and he said the story. ohh that what's happen Rin ask Einz if he can help him Einz accepts it without thinking.
He said it to Hercius but Hercius disagrees with it he thinks that it might be trap
because they just done fighting.Einz investigates what happen in that kingdom to make sure its not a trap. He sees a knights forcing people to work when he's about to get in the kingdom something stopped him, there's a barrier that stops people from getting out or in. When he's looking to the kings castle he sees the mages destroyed the statue there and he immediately go back to say it to Hercius.
Hercius joined the planned after what Einz says they made a plan to get it back.
They attacks that kingdom Einz destroyed the barrier and Hercius knights get in
they fought and win .
After that Rin becomes the king again and they become allied.