Chapter 306

Boundary (境界) is the 306th Page of Yūki Tabata's Black Clover.

Summary
Yuno Grinberryall fires his Spirit of Euros spell and manages to pierce Zenon Zogratis's chest. As Zenon thinks about how powerful that spell was, Yuno proclaims that their tenacity won this fight.

Zenon thinks back to when he was injured and his siblings, Dante and Vanice, insulted him for being weak. Zenon's oldest brother, Lucius told Zenon to not worry since Zenon had the greatest aptitude for being a devil host like him. Sometime later, Zenon was being assaulted by John, whose father was in the Mage Defense Force, because of his Bone Magic. As John went to attack Zenon again, Allen Fiarain showed up and stopped him. John and others ran away, which Allen called them an embarrassment to the Mage Defense Force. Allen introduced himself to Zenon and mentioned how strong Zenon's magic looked. Allen and Zenon then headed to a roof top, where Allen commented about the situation the Spade Kingdom was in. Allen proclaimed that he would be the commander of the Mage Defense Force to give hope to the citizens of the Spade Kingdom, to which Zenon responded that he would also become the commander of the Mage Defense Force. Allen said that that made them rivals and that they would compete to see who became commander first.

Over the years, Allen and Zenon trained to get stronger and received their grimoires. Zenon even apologized to his oldest brother since he did not want to become a devil host. Allen and Zenon managed to get into the Mage Defense Force and were assigned to the fourth division. When a dungeon was discovered within the Spade Kingdom, the fourth division headed out to explore it but found a devil. Zenon figured that he could defeat the devil with his ultimate spell but noticed that the devil had no openings. Allen said that he could not lose here since he was going to be the commander of the Mage Defense Force. As Allen charged, Zenon said that Allen would die but noticed that this was his chance to kill the devil. Zenon also figured that he would kill Allen too, and thought about what would happen if he did not kill the devil. Zenon decided to use his spell and killed the devil, along with Allen. Zenon thought about how emotions and tenacity meant nothing without power and started to cry. Zenon started to think about how power was everything and how the weak should be discarded. Zenon also started to wonder about the power of the devil and asked his big brother to make him a devil host.

As Zenon drops to his knees, Zenon meets with his devil, Beelzebub, and says that they should make a deal.