I Was Reborn as a Heroine Puppy

The protagonist in the novel is a puppy who is reborn as the heroine. A year later, I had the system and began to lead my master in counterattack training. He keeps getting stronger, and finally becomes a unified commander, killing all over the world. In the end, he fights the villain to the death for the heroine, and unfortunately dies. After that, the heroine travels all over the world to save him, and exchanges her own life for the hero. This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.