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.

Magic Knight Rayearth 2 - MangaDex

Rakudai Kishi no Eiyuutan - MangaDex

Kingdom Mangadex

Sakyubasu ♀ ni Kyousei Tenshoku Saserareta Ore ♂ - MangaDex

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

Knight's And Magic

List of Reincarnation/Otherworldly Manga~!

Knights of Alfheim - MangaDex

MangaDex

Maseki Gurume: Mamono no Chikara wo Tabeta Ore wa Saikyou! - MangaDex

Mahousekai no Uketsukejou ni Naritai desu! - MangaDex

Furuki Okite no Mahou Kishi - MangaDex

Shoujo Kishidan x Knight Tale - MangaDex