My Summons Are Mythical Beasts

Demons and Beast descended, terrorizing the whole world for the past hundred years. Everyone can awaken a grimoire and summon a beast during their age of ceremony. Lucas, awakening the weakest grimoire, also awakened the weakest beast- a small dog with no combat capabilities. Fortunately, as a transmigrator, Lucas also mysteriously awakened a system that allows him to evolve his summons into their mythical beast counterpart. Follow Lucas and his journey to greatness as he evolved his beasts into never been before seen mythical creatures.