Guardian

There was a hero with strength that swore to protect the land from evil one fateful day he fought the demon king but it was neck and neck but the demon lord charged at him and pinned him down it was over but last minute he used a spell to slay the demon but sacrifice himself for the greater good and then he was warped to a different realm where he could get a new body but he had to use someone he trusted so he picked his cat he still has powers but he can no longer talk but rumoured to train a person that could be his apprentice