The Magus Lock wasn't a technique, it was rather a magnum opus, a life's work a ''Magus'' could and would spend their entire lives perfecting.
The Magus Lock was essentially a permanent Visualization built within one's Spiritual Sea, a lot like Ryu was already used to. And much like the [Divine Chaotic Annihilation] Visualization of the past that used to perpetually protect Ryu's mind, so too would the Magus Lock, but via a much more profound method.
While [Divine Chaotic Annihilation] relied entirely on brute force and the use of an esoteric law, the Magus Lock, while it too could rely on brute force sometimes, could also make use of softer method and other forms of subterfuge.
The Magus Lock was precisely that, a lock placed on the mind that made it difficult to access the core of one's soul.
Mental Realm Masters had all sorts of obscure and hard to deal with abilities, this was part of the reason they had been banned in Ryu's home world, outside of the machinations of the Martial gods, of course.
They could read minds, control minds, manipulate memories, and even worse the most powerful and skilled among them could accomplish such things with you being none the wiser.
The only way to protect yourself was to either be quasi omnipotent and all knowing, or to preemptively prepare yourself, and that was where the Magus Lock came into play.
According to the Magus Sky God, unless you could forge your own soul protection treasure with all of your knowledge as a Magus built into it, it was best not to rely on them at all. It was impossible for soul protection treasures to block against all methods unless they were at a certain level and the Magus Lock was far more reliable.
Using the Magus Lock was like surrounding your soul in a maze-like construct, filled with illusions and false walls only you knew how to get through, and also the occasional simple and stronger barrier of defense. The more complex the Magus Lock, the more difficult it was to deal with, and the more secure your mind would be.
The Magus Sky God left behind several potential base Magus Locks that his inheritor could fuse with immediately. It took time, patience, and a lot of hard work to build up Magus Locks on your own, so the Magus Sky God left behind several foundations to pick from.
Depending on the foundation Ryu picked, the ultimate form of Magus Lock would likewise be different.
There were three choices.
One focused on the most on the maze aspects, making one's mind difficult to navigate. This choice would make one's mind a lot more difficult to read and control. It was by far the best in this aspect.
The second aspect focused a lot more on false walls and illusions. This choice made the mind easier to penetrate, but hard to extricate oneself from. It was a double-edged sword of sorts and could be used by those confident in their raw abilities. It was excellent at trapping and ensnaring.
The final aspect focused on solid and sturdy walls. This made the mind incredibly firm, but it could also be brittle depending on the situation. In addition, it had natural defense against attacks, but it was weaker against more subtle manipulation like mind reading and control.
Of course, while all three of these aspects had their weaknesses, it wasn't to an exaggerated point. It was all relative. Any one of these three aspects had stronger defense even in their weaknesses than most similarly leveled soul protective treasures. This was where the strength of the Magus Lock really shined.
Even so, Ryu completely ignored these foundational methods and began to build his own.
There were two reasons why one would want to build starting with these foundational molds.
The first was the difficulty. understanding the runes needed to build a Magus Lock was a tall task and might take years in and of themselves for someone who was less talented, but to then be able to use these Runes to build adequate defenses without your own experience would be nigh impossible in a short time frame.
The second was plasticity. This would be a relatively new concept to anyone who came across it and it would be difficult to decide exactly how to build up one's defenses immediately even if you perfectly understood the Runes needed to do so.
The first problem wasn't even a problem for Ryu. He had his Realm Heart which had been perfected to the Immortal Realms, meaning he could see through Immortal Grade secrets with absolute ease. Until he reached the Cosmic Seed Realm equivalent for his soul, these would be all the runes he would need.
In addition, even if he didn't have his Realm Heart, he still had his Dao which was exceptionally good at comprehending such things. Now that he had the Fundamental Runes so perfectly laid out and labeled for him by the Magus Sky God, this was as easy as breathing to him.
As for the second problem, Ryu wasn't a normal inheritor. He was a person who was already used to using Visualizations to protect his mind, so he had a subtle feeling for it already.
And, once again, even if he didn't have such experience, he could see through the secrets of the three foundational molds the Magus Sky God had left behind and piece together their concepts to form his own.
Just like this, Ryu planned to use some of the concepts the Magus Sky God had self-created, the false walls, the maze and the sturdy defenses, and he would also infuse his own concepts. These methods would rely on concepts from [Divine Chaotic Annihilation], which could swallow up qi of all types and spit out more Spiritual qi, [Immortal Sakura], which was adept at taking on frontal attacks and turning them into glancing blows, and most importantly, his own Spacetime Soul Nature would be his greatest defense.
It only took Ryu a few minutes to come up with the perfect foundation for his Magus Lock using these concepts and soon delicate dark gold runes were dancing within his Spiritual Sea. In less than half an hour, Ryu had defenses he felt made him immune to any soul attacks beneath the World Sea Realm, and even for attacks at that level he felt like he could tank them.
His aura completely changed, and his gaze flashed with a dark gold hue before it slowly faded.
Ryu's hair fluttered in the wind as he took a step forward, vanishing into thin air.
Dark gold runes danced around his body and within his irises as he moved forward faster and faster.