Agis: Rising Star

Vedas Agis was born (or reborn) as the third son of a noble family, he was reincarnated after his death in a vast world of magic and adventure, and had vowed to embark on one of his own.
But this isn't about that, this is the sequel, Vedas is already an accomplished man of his own, he's known far and wide as a formidable Hero and a very powerful Wizard, and he's been spending his early retirement as a Professor at the foremost Academy in the world.
But all that changes when one of his House's senior knights visits, bringing with his sad and grave news....
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Author's note: As the synopsis indicates, this isn't a Progression Fantasy, but rather the sequel of one, the MC is already kinda overpowered so this is gonna go pretty low on combat just to not make it too boring. This is firmly kingdom building, the MC is gonna develop his land through alliances and economic developments, and it's heavy on the technical jargon.