It Makes Sense for the Squishy Necromancer to Be Afraid of Death and Increase His Body Completely, Right?

In his previous life, as a young middle school boy who traveled through time, his blood had not yet cooled down. He saw the country of Yan, who was of the same origin and species, in trouble, and was easily deceived into becoming the guardian of the empire. After guarding the Yan Kingdom for three years and three years and three years and three years, his application to enter the maze of national destiny was rejected every year, and he finally fell into a desperate situation. If that's the case, then don't even bother with it, and just drag the world along with you! Unexpectedly, after sacrificing the world, he could restart his life. In this life, the blood has gone cold, facing the country of Yan who has the same origin. This guardian will do whatever he likes, but he won't do it anyway! Seize the opportunity, make up for the shortcomings, and never return on the road of the Blood Ox Necromancer, overwhelming everything! I, the Necromancer, rule over the undead, and the undead natural disasters run rampant!