The Magic in this Other World is Too Far Behind! Volume 3 by Gamei Hitsuji

Suimei continues on his journey towards the Nelferian Empire, now with Lefille in tow. He has to add her new “problem” to his growing to-do list, but it won’t be the only thing he’s worried about by the time they get to the capital city. A strange military figure doesn’t seem to take kindly to their presence there. Meanwhile, Reiji, Mizuki, and Titania’s demon subjugation is put on temporary hold for an emergency rescue mission. They’ll make an interesting discovery or two along the way. And just where is Felmenia in all of this?