He saved the village. He was hailed a hero. He gave his new born son the task of protecting the village. He wanted his son to be hailed a hero.
Watching as his son grows up, he sees him suffer, abused, tortured and for what? A demon they call him and everyday as he watchs, something breaks within him until the final straw.
His poor baby boy. His pride and joy.
Dead at the age of five.
That's when he's given a chance by the Shinigami, a second chance in life. A chance to get his revenge on the village that killed his baby boy.
Konoha wanted a demon and they got one in the form of their Yondaime.