Sasha Granberg died a dog's death in the final war against the Dark Lord. A mere lowly soldier, he gave up his life in order to protect his captain. However, when he was given another chance to return to his six-years-old self, he was determined to set everything right.
No more wasting time! No more playing the prodigal son! He would train until he puked out blood, and then become the hero who will defeat the Dark Lord!
And so he did, turning into the world's savior. A life of peace followed, until his life finally reached its natural end at old age, his deathbed surrounded by his loved ones.
And then, he got sent back to his six-years-old self. Again.
He already defeated the Dark Lord, he already reached the happy end! What was the point of getting rebirth once again ah?
Thus he decided, this time he wouldn't bother with anything else and just do whatever he wanted...