The Forgotten God

A college student, who has been living normally by himself since the age of 18 gets killed by his own sister, but stuck in the afterlife that he was sent to, he finds himself in a realm meeting a banished god who claims he is "The God of Darkness".

when speaking to this god, the god then offers him another chance at life at the condition of eliminating another god, at this, the boy willingly accepts the dark gods proposal and his life begins anew.