He gives a classic monologue!

"Heh... Well, since you asked... Ever since my youngest days, I always admired and adored the Holy Swords," Valper began to explain, clearly reminiscing. "The idea of wielding one would always make my heart dance... But then I was told I had no aptitude for them, and that briefly made me fall into despair. But because I myself could not wield them, I became enamored with those who could, and began to research how to create ones who could wield such blades. And thanks to you all... I was able to complete my research," he smirked as Kokabiel watched in amusement. No one else was moving, instead observing this confrontation.

"Complete!? All you did was decide that we were failures and dispose of us!" Kiba shouted.

"I realized that a certain gene was required to utilize the blades... But none of you possessed enough of the gene to wield the swords," Valper shook his head. "But then, I had an idea. Could I not simply extract such genes from some subjects, and implant them into another?"

Kiba froze in horrified realization as Xenovia grit her teeth. "...so that's what was put inside of those chosen up on being blessed..."

"That's right... The genes were crystalized upon extraction. Like this," Valper noted, pulling a crystal out of his robes to show them. "Thanks to this, my research was able to take leaps and bounds forward... But the church considered me a heretic, and banished me for my actions, even as they took my work to use for themselves..." He glanced towards Xenovia and Irina. "Looking at you both though, it seems my research was passed on. Even though that hypocritical Michael himself condemned me and my work..."

Kiba grit his teeth, rage overtaking him. "You're telling me that you killed me and my friends, just so you could take our genes?"

"That's correct," Valper shrugged carelessly, as if life meant little to him. "I was able to keep four crystals, and used three on Freed here. This is the last one..."

"Hehehe," Freed chuckled gleefully. "Others who tried couldn't handle it and died. I'm just that great~!"

As Kiba prepared to charge in a rage, he growled, "You toyed with so many lives, just to satisfy your own desire! I'll make you pay!"

"I'll show you, and those fools in the Church, and the Angels they so foolishly follow! Sacrifices are necessary for progress!" Valper laughed. "And the fruits of my research are plain to see!"

"Funny how anyone who talks about "sacrifice" are almost never the ones being sacrificed, but the ones sacrificing others," Issei snarled in shared rage with Kiba, about ready to follow through on his word to help Kiba kill this pathetic excuse for a human being.

"You lack vision," Valper sneered, before tossing the crystal towards Kiba's feet, brining him up short. "Here. You can have the dregs. It's but a shadow of what it once was..."

Kiba hesitantly picked up the crystal. This... This held all that was left of his friends... "Everyone... I'm sorry," he said, his voice cracking as he shook, tearing up. Then, without warning, the crystal began to glow, something even Valper did not expect, if his expression was anything to go by.