"Regarding Persona fusion, I can indeed offer some limited assistance. If you can gather specific Personas, I can synthesize them into new, more powerful ones... but this synthesis is not without risk of failure."
Kaslana crossed her arms, frowning slightly in thought before giving Ren her considered answer.
Kevin underwent the MANTIS modification surgery of the Chimera Project; his body contains factors from almost every type of Honkai Beast.
As a reflection of Kevin's life experiences and power, the Kaslana Stigma Space can simulate and reproduce the Honkai Beast factors within Kevin's body. Theoretically, through continuous experimentation with permutations and combinations, the optimal method for fusing multiple different Honkai Beast factors could be discovered.
However, this was limited to Personas that were Honkai Beast entities, like Ren's Huodou.
For Personas existing as Stigmata, those who were once human like Yae Sakura and Kallen, Kaslana had no method to fuse them together.
"Depending on the types of Personas you provide, there's a certain chance I can make them fuse into a new Persona. But the outcome isn't something I can guarantee one hundred percent. It might become stronger, it might remain unchanged, or the new Persona synthesized from two could even end up weaker than the original components. That's not an impossible probability."
Drawing upon Kevin's experience—surviving the incredibly low-probability Chimera Project as if favored by fate—Kaslana was confident she could prevent the Personas Ren provided from being utterly destroyed in the process.
But she could only guarantee the newly synthesized Persona would maintain its basic existence, nothing more.
The Chimera Project was tailored by the Previous Era's Dr. Mobius specifically for Kevin's physique and condition, sequentially cultivating Honkai Beast factors based on their compatibility with his body. Kevin's survival and subsequent gain of immense power were miracles among miracles.
Although most Honkai Beasts were like puzzle pieces from the Chimera Project, not every piece could fit perfectly with another. The compatibility and sequence of Honkai Beast factors were crucial.
Even the Kaslana Stigma Will needed to conduct extensive simulation experiments using Honkai Beast factors within the Stigma space, accumulating data and experience, before she could confidently perform Persona fusion for Ren.
Compared to the Previous Era's Chimera Project, Kaslana didn't need to implant Honkai Beast factors into Ren's body; she could manipulate the fusion of two Honkai Beast Personas externally.
Without having to worry about the compatibility between the human body and Honkai Beast factors or life-threatening risks, Kaslana's psychological burden was significantly lessened. Otherwise, she wouldn't have even suggested she could perform such an operation.
Kaslana's only remaining concern was that Ren might be unable to accept the potential failure—that the multiple Personas he painstakingly acquired could turn into a useless Persona weaker than the weakest original component.
"No problem, I understand. Persona fusion has never been a guaranteed thing, after all. I'm already incredibly grateful that you can help with fusion at all, Kaslana."
Ren saw Kaslana's hesitation and nodded reassuringly at the expressionless Stigma Will, offering a relaxed smile to ease her concerns.
Persona fusion inherently carried risks.
Even in the Velvet Room, the specialists in Persona fusion, a Fusion Alarm could randomly result in Personas deviating wildly from expectations—either stronger or weaker, like a total RNG gacha pull.
This was even more true for Kaslana, who admitted her skills were inferior to the Velvet Room's and could only serve as a lesser alternative. If she failed a fusion, Ren would have absolutely no complaints.
After all, just having someone who could assist with Persona fusion was already fantastic, infinitely better than nothing.
Thinking optimistically, Ren figured this was basically like being permanently stuck in the Velvet Room during a Fusion Alarm. Maybe one lucky fusion could change his fate entirely, pulling a Yoshitsune and beginning the delightful journey of charging up Hassou Tobi.
...Of course, if a Persona fusion did fail, it would definitely still sting.
"Anyway, let me ask beforehand: Kaslana, do you have something like a Persona Compendium function here? You know, the ability to instantly re-summon Personas that have disappeared from one's heart?"
If there was one system feature perfectly paired with Persona fusion, it was undoubtedly the Persona Compendium, which registers information on all Personas.
Even if a fusion failed, one could immediately pay a fee to re-summon the lost Persona, acting as a safety net for fusion.
If Kaslana could re-summon lost Personas, Ren could proceed with fusion completely worry-free.
"Regrettably, I cannot fulfill that request."
Kaslana gently closed her eyes, giving Ren a negative answer.
Although she could summon the numerous Honkai Beasts constituting the "Chimera" within the Kaslana Stigma Space, those beasts were mere phantoms—illusory beings confined to the Stigma Space, unable to be subdued by Ren to fight for him.
Awakening a departed Stigma Archetype from its eternal silence was an exceedingly difficult task. Kaslana couldn't meet Ren's condition.
"I see. That's a real shame. If I could re-summon Personas, I was thinking about trying out what the Great Thief's Baton feels like." [Reference to Joker's ultimate melee weapon in P5R, obtained via itemizing Arsene]
Though the answer was expected, Ren's tone still held a hint of disappointment.
Kaslana hadn't yet answered whether she could weaponize Personas, but Ren wasn't overly concerned about that.
After all, Hare had essentially demonstrated the act of executing a Persona into a weapon before Ren's eyes.
Shadows and Personas weren't fundamentally different. Hare had combined the residual power of Yae Sakura's Shadow, Higokumaru, along with Sakura's Desire Stone and Treasure, ultimately transforming them into the extremely powerful katana, Jizo Mitama.
If the need arose later to convert a Persona into equipment, Ren could confidently entrust that task to Hare.
...Speaking of which, weapons created from Shadows and Personas should probably be different, right? If he were to execute Persona Yae Sakura, perhaps a weapon completely opposite to Jizo Mitama would appear.
...Better not think about it.
This wasn't like the game. Yae Sakura felt like a living, quiet girl to Ren, not just data or an item.
Even knowing that Sakura wouldn't truly die if subjected to the electric chair execution and could meet Ren again, he couldn't bring himself to execute her.
"The method of transforming Personas into items... you should seek that within the true 'Velvet Room.' I cannot assist you in that regard."
Turning Honkai Beasts and Stigma Archetypes into usable weapons struck Kaslana as an outlandish request.
While the Previous Era did extract body tissues and cores from various Honkai Beasts to create powerful weapons, even crafting Divine Keys from Herrscher Cores, those were all done to compensate for their own shortcomings.
Ren had already subdued Honkai Beasts and Stigma Archetypes as Personas, able to command them in battle as extensions of his will. He should have no need for the redundant step of converting Personas into weapon forms.
Kaslana couldn't comprehend Ren's line of thinking and could only offer no help.
In her view, perhaps only that Great Magician Vill-V in the Elysian Realm could perfectly sync with Ren's wavelength and understand the importance and perhaps even the "fun" of these "executions" he spoke of.
If Ren ever did enter the Elysian Realm, Mobius might not offer help, but Vill-V would undoubtedly take immense interest in this unfamiliar visitor.
"More so than Persona fusion or itemization, what troubles you most right now should be that your 'capacity' is nearing its limit, preventing you from acquiring new Personas... For me, that problem is actually the easiest one to solve."
Kaslana slowly opened her eyes, her ice-blue gaze resting calmly on Ren standing before her.
She had instantly seen through the real issue plaguing Ren and claimed she held the solution.
"Really?! Then please, I'm counting on you, Kaslana!"
Hearing Kaslana's surprising answer, Ren's eyes instantly lit up. A look of joy spread across his face as he made his request to the Kaslana Stigma Will.
If the Persona slots in his heart could be expanded, Ren wouldn't need to rush into the blind-box gamble of Persona fusion.
His current Persona lineup was already quite comprehensive. Fusing some of them away might actually decrease his overall combat effectiveness and cause him to lose the advantage of covering most elemental affinities.
"When you subdue Kallen as a Persona, I will simultaneously bestow upon you a small portion of my own power. This power will be sufficient for you to break through your current shackles and grant you the underlying potential to hold more Personas."