Lightning. Swoosh. Pierce.

Eren lodged his blade into the bear's heart from behind him. The back of his exoskeleton had been damaged by the Mammoth's trunk attack in the previous fight. Eren had a relatively easier time combating the beast up to this point.

Roar.

The beast roared and got on all fours again. Despite his heart being pierced and his body being invaded by Eren's lightning mana, the beast's sheer tenacity allowed him to fight until his last breath.

The beast turned fiercer after it was clear to him that he wouldn't survive the fight. Eren had to make use of his infinite mana reserves to take care of the beast.

Thud!

Eren had managed to kill the bear after about 15 minutes of battle. He was made aware of many of his shortcomings during this battle. He didn't have a steady rhythm in his attacks. As if he was missing the spells or skills that could connect all his moves seamlessly into one precise strike.

However, in the end, he was happy. Because now he had two dead mana beast bodies as his reward for the fight he had fought. That was not all. He also started feeling some activity in his mana circuits that had gotten activated on their own.

Eren's experience of so many close calls in this battle stimulated his potential. His usage of the infinite mana core had put pressure on the mana circuits, enabling them to expand and get more refined in the process.

This expansion of mana paths and activation of mana points then made way for accelerated mana flow throughout his body. He had maintained the same state for so long under pressure to survive. Therefore, it was only natural that his dormant potential to become a ranker responded to his efforts by offering back-to-back stage breakthroughs.

Eren took a long breath and stood straight while he experienced his breakthrough. It was like his mind was connected to a higher consciousness that couldn't be explained with words.

As Eren indulged in his breakthrough, a Rank 1 mana cloud gathered around him. A ranker's mana circuits would be refined during this painful yet enjoyable process.

***

The universal laws would rearrange the rankers' mana circuits anew with every stage breakthrough. With a rank breakthrough, the same process would happen over and over again until a fully functioning mana circuit system had been created from scratch. This was the reason ranking breakthroughs had more severe bottlenecks than stage breakthroughs.

Mana cores would undergo a phase change as a result of the breakthroughs. They would also create new mana points and mana pathways, modify the existing ones or destroy them. In the end, they would also restructure them according to the ranker's personal choices reflected through his class, preferred spells, and other personal choices.

The Mana circuit would be in its preliminary stages at the start of Rank 1. It would get more refined than the last time with each stage and ranking breakthrough. What might seem like a night sky with endless stars would slowly develop a pattern of constellations that suited the ranker's personal choice and class.

Eren's class was that of a battlemage. There were no specific ways his mana circuits would be defined since the battlemages were just like what Miranda had described them to be. Jack of all trades.

Therefore, it was particularly difficult for a battlemage to advance into their ranks and achieve breakthroughs. Their mana circuits would have more intricate details than the rest of their peers who had chosen a fixed path for themselves.

The difficulty for battlemages would only increase the higher they climbed the ranking ladder. Therefore, only rich rankers and rankers who were blessed with good fortune through being guided by high-ranking entities could walk steadfastly along their path to becoming battlemages.

The trade-off for this difficulty was being able to use a wide range of spells from almost any class. A skilled battlemage would effortlessly shift between his roles to suit his needs at the time.

It was not that only battlemages would be able to pull something off like that. Even normal rankers with rigid paths could use rank-compatible spells of any element. The only difference is that they would have reduced spell output except for the element they specialized in.

This cross-element element compatibility could be used to its fullest when the rankers had a hybrid affinity and chose the battlemage class. Their complex mana circuits would allow them to use any of the great element spells their hybrid element was compatible with along with the hybrid element itself as if they were born with those affinities.

The effectiveness of spells mattered a lot when it came to casting spells. For example, someone with fire element affinity could use 10 percent of their mana for casting a fireball spell that would deal 100 units of damage over time.

Whereas, someone with the same rank but reduced fire element compatibility would have to spend 30 percent or more of their mana storage to achieve the same damage output. The percentage would depend on how far they were from having true affinity to the element.historical

As a result of hybrid element compatibility and the battlemage class, rankers could cast spells in the hybrid element as well as the great element from which the hybrid element was derived with ease and efficiency. Even then, the hybrid element was the most effective. However, other elemental affinities weren't far behind for battlemages with hybrid elements.

The battlemage class allowed one to be flexible about any role they wished to take in a team. They could be rangers, close combat experts, berserkers, mages, or even healers if they had the experience, practice, spells, and gears to pull off the job.

Since Eren had selected a battlemage class for himself, his circuits expanded and became even more complex than they were. During the breakthrough, Eren smiled mirthlessly as he contemplated the possibilities he held with his class. Sometimes having many possibilities only complicates the matter after all.

Still, he didn't regret choosing a battlemage class. It was the only class that could allow him to make full use of his advantage. And that's what he was planning to do. Now he just needed to be sure that he found his own style that could make use of his class and infinite mana core to his fullest.

***

Eren's recent battle became the trigger point for him to achieve multi-stage breakthroughs. He was able to enter the fourth rank straight away because of his accumulated experiences, his diligent routines, and his infinite mana core.

Both of Eren's mana cores had changed their phase. They were in their liquid phase right now, spinning around themselves silently when Eren was done with his breakthrough.