Rebirth: The Heaven Suppressing Tower

A top assassin, betrayed by his beloved, is reborn with the supreme divine artifact, the Heaven Suppressing Tower, into a different world as a useless prodigy. With the warmth of his new family, he awakens the ancient tower's power, shattering enemies, revitalizing his clan, and stepping across the heavens, gradually suppressing the entire otherworld! — Description from novelcodex.org