Supreme Magus

Back when Balkor had developed memory crystals to guide his thralls, he hadn't had to deal with conflicting willpowers since what he imbued them with was his own personality. The limit of his memory crystal was that they couldn't be used by other people and that the knowledge stored inside of them didn't last for long.

Balkor's method consisted of storing the crystals inside a powerful array that insulated them from the world energy. The gemstones were left with nothing to feed on but the magical formation which was fueled by Balkor's mana.

The world energy stored inside the crystals would be slowly replaced by his spell that was imbued with his willpower, grudge, and anger, turning them into memory crystals.

The problem with this method was that once the crystals were removed from the arrays, the natural flow of world energy would be restored, flushing the mana out.

It was the reason Balkor's attacks on the Kingdom and his undead couldn't last more than three days.

It was still a perfect method to craft a powerful and loyal undead army, but pointless to anyone but him.

People like Jirni would have been unable to trigger his mana and even if they did, they would have been flooded by Balkor's stored emotions, ending up brainwashed or dead.

Lith had found the solution to both problems by studying of the Origin Flames flasks and the orc shaman's crystal bearing Vastor's device.

From the former, the research team had learned how to create an enchantment capable of storing two imprints in parallel. The method allowed the willpower of the maker of the Origin Flames to be retained without interfering with that of the buyer.

To achieve this effect, solely the inner half of the crystal/flask had to be imbued with willpower from the caster, leaving the other half free to host the willpower of the buyer thanks to a special insulant placed in between the layers.

Much to no one's surprise, the insulant required was Darwen.

Placing the Darwen's gel in the flask was easy since each flask actually consisted of two opportunely shaped crystals fused together. Using such a method to reproduce the Spell Hoarding Cube was impossible though.

To hold both spells and willpower, the crystal needed all of its power, and cutting a gemstone into two would also halve its effectiveness. It was the Cube's role to bear the layer of Darwen and allow the willpower of its wielder and that of the spells' casters to interact safely.

Yet it would still be useless if not for the orc shaman's crystal that Lith had stolen during his boot camp. Thanks to Vastor's device and the notes left from the late Manohar, the Archmages had discovered the secret to crafting a perfect memory crystal. 

By tracking the mana imbued by the shamans over the centuries, the device had allowed the Archmages to find anomalies in the crystals, and only after a careful study had they understood the significance of the phenomenon.

Injecting willpower into a crystal like the shamans did or using both mana and willpower like Balkor were both highly inefficient methods due to the dynamic equilibrium that the world energy inside the crystal reached with the external one.

Without constant injections of mana and willpower, it took years for a crystal to retain even a shred of its user's personality simply because their essence would be scattered throughout the crystal and the stored mana would last for a short time.

To make the effect permanent, the mana imbued with willpower had to become an integral part of the crystal's structure. After all, mana crystals were world energy that had taken physical form after being subjected to high pressure for a long time.

Aside from the fact that mana held the life force of its owner instead of Mogar's the two forms of energy were identical. 

Vastor's device had shown the Archmages how to recognize the areas of a crystals that were still sensible to growth after being mined and that could accept their mana. Once it crystallized, the mana would retain the willpower and spells of its owner without being affected by the constant flow of world energy through the gemstone.

On top of that, once the stored spell was spent, the memory crystal would be capable of storing a new spell from a different person since the crystallized mana formation would have lost its initial imprint.

The only thing that the research group had failed to uncover was how Tyris had managed to have the same crystal hold multiple spells from different people at the same time.

For his Spirit Memory Crystal Lith had no use for the Darwen since Spirit Crystals wouldn't answer to anyone but their maker, but he still had to permanently add his mana to the crystal's lattice.

After turning the world energy inside the gemstone into his own mana thanks to his Spirit Eye, the task was even easier. He only had to fight the pressure of the world energy coming from the outside and make sure that it didn't seep inside the crystal before he was done.

The Spirit Magic that painted the crystal emerald answered his will like an extension of his body, helping Demon's Grasp to find the areas of the crystals with enough natural imperfections.

It was there that Lith would increase the density of his mana until it crystalized, filling the holes and reshaping the lattice into a perfect form. This way he would not only be capable of indefinitely storing his personality and spells, but he would also improve the crystal's quality.

Solus joined him, using their mind link and the fact that their energy signature was the same to pour her mana as well inside the right areas of the gemstone, increasing the pressure and accelerating the crystallization process.

Yet it still took them several hours.

It took a mana geyser centuries to condense the world energy into a crystal, but luckily they didn't have to create one from scratch. They just had to use the already existing crystal lattice as a scaffold and fill the blanks.

The process required unrelenting focus rather than raw power. The mana had to be focused on the imperfections and Lith and Solus had to keep the pressure high enough to make it slowly condense.

The alterations they caused were so small that they were invisible to the naked eye and even to a breathing technique.

Without Vastor's device, they would have never discovered the anomalies in the orc's crystal and without Balkor's knowledge of memory crystals, they would have never understood their significance.

After staring at Lith and Solus with Life Vision for a while and failing to understand what was happening, the others got bored. They walked out of the Forge, leaving a note where they asked Lith to call them before he completed the Golem.

Watching a couple of mages grunting and staring at a crystal was as interesting as watching the paint dry.

"If the process to create a Spirit Memory Crystal is so long and you had no intention to share the details with us from the beginning, why didn't you do it before the Forgemastering process?" Protector asked once Lith had recalled them to the Forge.

"I would have loved to, but sadly a Spirit Crystal has to be attached to an artifact right after it's crafted."