From Ashes To Scales

After a tragic death in modern Japan, Murakami Yamada is reborn as Magnus, the youngest son of a viscount in the fantastical world of Magnolia. Gifted with the unique skill Experience Boost, he finds purpose in his brother’s guild, but ends up being cast away for being too weak. Faced with death he undergoes a shocking transformation into a lizardfolk and rapidly becomes one of the most powerful mages in the world. Cast out and misunderstood, Magnus embarks on a journey to forge his own nation, defying prejudice and wielding his newfound identity to reshape a world torn by war and magic. In this isekai epic, one man’s quest for belonging becomes a legend of sovereignty. — Description from novelcodex.org