Knights & Magic - MangaDex

A mecha otaku is reincarnated into another world as Ernesti "Eru" Echevalier. In this magical world, the country is protected by knights who pilot a kind of large humanoid weapon known as the Silhouette Knights. Dreaming of piloting these robots, Eru and his childhood friends, Archid and Adeltrud Olter, study Magic and work toward their goal together.

List of Reincarnation/Otherworldly Manga~!

Knights & Magic - MangaDex

Haikei Kouri no Kishi to Hazere-hime datta Watashitachi e Manga

Knight's And Magic

조선생님 - MangaDex

mangademon - MangaDex

Slave of Black Knight - MangaDex

Knights & Magic - MangaDex

DISC] I Found a Female Knight in a Rice Field, in the Countryside They Think She's My Wife - Chapter 1 : r/manga

Wuming Qishi - MangaDex

Knights & Magic - MangaDex

The Seven Deadly Sins: Four Knights of the Apocalypse - MangaDex

Mahou Tsukai no Oshigoto - MangaDex

MangaDex