Heroes Just Aren't enough?

In world besieged by a Newly reincarnated Demon Lord with an unquenchable thirst for conquest, Lucien Hearthfire the ruling god of the world of Altasia has summoned countless heroes to defend his world only for every single one of them to fail miserably against this daunting threat. Tired of his home being ravaged by this villainous threat Lucien does the unthinkable and decides to reincarnate and take the mantle of his worlds hero himself. will Lucien be able to fend off the invading forces that besiege his world or will he fall to the flames of conquest?