Berserk

Coal was fast enough to escape the tunnel before Zero unleashed the fire skill. Zero was immune to fire damage, but Coal wasn't. At this point, Coal had no idea whether Zero cared for him or not, he came to save him... at least he believed so. But at the same time, he did things like almost killing him with fire.

Since his resurrection Zero barely paid him any attention, not like Zero lost anything from resurrecting him anyway. Coal had conflicting emotions when looking at Zero.

Zero glanced at Coal and wanted to say something, but kept it to himself.

A system screen popped up before his face.

[Warning! Pet Coal (Midnight Wolf) is losing loyalty. Corruption by an unknown lifeform progressing further.]

Zero was dumbfounded. He just resurrected this stupid dog and he is already thinking of betraying him? Why exactly would Coal even betray him, there was no reason, right?

Zero didn't understand why Coal was so upset with him, they couldn't talk it out since Coal was unable to talk. All he could do was guess, but to him, he didn't do anything that would anger Coal.

Coal wasn't showing it on the outside so Zero wouldn't kill him or something, but he was angry at Zero. This wouldn't have happened in the first place if he just would've come with him instead of going through the portal himself.

Zero turned around to face the invisible wall once again. He thought about using Disintegration on it, but shook his head and went back to the cave. If it would reflect disintegration back on him he would die instantly without the slightest chance of survival.

Coal stood there, his eyes following Zero as he went past him deeper into the tunnel. Would he not even mount him so they could go faster? He silently followed Zero, they were moving slowly, Zero didn't run as fast as he could, he just casually walked down the tunnel.

The more they walked the more Coal questioned this situation and their relationship. Zero had turned his back to him, he hadn't said a single nice word to him since he was resurrected, and not a single word since they came down into this tunnel.

In reality, Zero was just messing around with the system and analyzing this Blacksmith Celestial Art he got as a reward. It wasn't anything special. He already knew almost everything that this reward got him.

He didn't even kill the final boss yet, but he had already completed 2 achievements. Originally achievements would only be unlocked after the first death of the final boss, but that didn't seem to be the case for impossible achievements.

They walked and walked, and walked... a couple of days had passed already. At this point, Zero was just using this time to relax a bit and set his priorities straight. Coal on the other hand was using this time to misinterpret things that Zero did up to this point.

He was overthinking and coming to his own conclusions without ever talking to Zero about it, but he couldn't, even if he wanted to.

A screen popped up before Zero's face once again.

[Warning! Pet's loyalty reached a critical state. Pet is about to go berserk.]

The system's voice was cold, Zero was startled by this sudden warning. Why would Coal's loyalty plummet if Zero didn't do anything at all to him?

He quickly turned around and saw Coal standing there looking at the ground. Zero had prepared his scythe and gulped. Even though Coal's level was reset just like his, Coal never lost the perks boost. Coal did indeed become weaker because his giantification would only boost his current strength, but it was still way more than Zero's. 

Coal started foaming at his mouth, is this the berserk state?

[Warning! Connection with the pet has been lost. Quickly subdue the pet to restore the connection. Time limit: 5 minutes]

Hearing this Zero couldn't help but grin slightly, he didn't know why he did that, but he was excited. Something deep within him was burning up.

This was something else he gained when he was transported to this world. This was battle hunger. It activated when he formed a star to destroy the world. He didn't overreact at that time. 

It was simply this instinct that was planted inside of him. 

His scythe went up in flames. As long as it had divine energy he would be able to release overpowered versions of his skills.

Coal dashed toward Zero and roared, his consciousness was fading and he couldn't control himself anymore. He wouldn't attack Zero no matter how displeased he was with him. This was because he feared Zero. This madman would kill him any day of the week if he had a reason to.

But since he had gone berserk this reasoning was no longer with him.

Zero blocked Coals attack and was sent flying backward. Just as expected, he was no match for Coal in terms of strength. All he had to his name was his scythe and the ring of protection. But this should be enough.

Zero flung toward Coal and managed to scrape his side. It went up in flames, what a horrific sight. Coal roared up in pain and dashed toward Zero.

Zero was jumping around like a fly, cutting Coal all over. They didn't even notice that they already arrived at the cave. Coal was severely wounded while Zero barely sustained any injury.

Coal was still burning with the green indistinguishable flames, his health ticking away every second. 

[Time Remaining: 3 minutes]

A shallow shriek suddenly echoed through the cave. It was a little monster that Zero had somehow missed. Coal killed it with a stomp. Who dares to interrupt their battle?

[Warning! Warning! Warning!]

The system echoed in his head multiple times.

[Advice - Run.]

Zero was dumbfounded. What's up all of a sudden? Why is the system so distressed? Did another octopus from hell appear or what?

Suddenly a screen appeared above Coal. It wasn't very detailed like it would usually be, it displayed only 2 points of information.

[Coal]

[Level: 4]

[Combat Strength: 26.000] 

[Zero]

[Level: 1]

[Combat Strength: 12]

Zero: ...