"Is it alright if I use your laptop?" Leon leaned against the doorframe of the lab, looking in on Wesker as he looked at something through a microscope.

"Of course."

Leon watched the blond man for a few moments longer before turning and making his way into the study. Surrounded by dozens of books lined up on tall, wooden shelves was a desk with the laptop and a few papers with notes scrawled over them. Leon flipped the screen open and waited for it to start up, leaning back in the leather chair. He wanted to see exactly how much his interpretation abilities had been heightened by the virus.

Leon opened the internet browser and loaded YouTube, debating on what he should watch. Improving his combat skills would be a great asset. His fingers ghosted over the keyboard quickly and he clicked on a video for learning several advanced forms of Wushu and Tae Kwon Do. It showed several types of moves, such as the 540 kick, butterfly twist and butterfly kick, tornado kick, and axe kick. His eyes followed every movement and he found himself understanding each attack with a concerning clarity. It was incredible, he could almost feel the links in his brain unlocking as it all suddenly made sense. Once finished, he clicked on the next video in the playlist.

Leon had spent most of the day watching videos in the internet, and he had fallen asleep with his arms on the desk and his cheek resting on his arms. A hand on his shoulder roused him and he looked up to see Wesker staring down at him.

"Shit... what time is it?" Leon yawned.

"Shortly after three in the morning. I've discovered why your regenerative abilities aren't working."

Leon straightened at the words and pressed his lips together. He was eager to hear why, but Wesker turned and strode from the room. Leon quickly got up and ran after him as he made his way back into the lab, watching as the blond turned and crossed his arms.

"Your virus lacks something, and without it the virus becomes unstable in a sense. It's like that of a chemical deficiency. Without this certain component, you lose your healing abilities and revert to your mortal form."

"Alright… and what is it I'm missing?"

"Hemoglobin."

"Blood? What? How does that even make sense?" Leon shook his head. He had to ingest blood? He nearly gagged at the thought. It didn't make him much different than a zombie.

"It is quite interesting that it's blood of all things, but I expected as much. Your virus was derived from mine, so naturally it would have a defect that would conflict with your immortality."

"Great. So how often am I supposed to… consume… blood?"

"As often as required, I'd assume."

Leon chewed on his lip and stared at the white tile floor. Could he even do it? He wasn't sure he could hurt someone. Sure, there were ways around drinking fresh blood, like blood bags or the blood from meat.

"Shall we test it?"

"What?" Leon raised his head as Wesker approached, rolling up his sleeves. His eyes widened as the blond produced a knife and easily cut his wrist, a line of crimson forming on the wound. Leon's mouth salivated from the sight and he trembled slightly. It was so wrong, but… it was Wesker, and he was offering. Wesker stood completely still, burning eyes watching Leon intently.

After a few moments Leon stepped forward, grasping Wesker's arm firmly. He leaned down slowly and ran his tongue over the wound, the taste of copper overpowered by a sweetness he had never tasted before. It was like a mix of ripe fruit and sugar. Leon moaned against Wesker's skin, closing his mouth over the wound and sucking hard, filling his mouth with more of the delicious liquid. His eyes fell shut and he lost himself in the taste of the older man's blood, no longer disgusted by the thought but instead enticed. His fingers curled more, digging into flesh and his teeth piercing the skin as he attempted to draw more blood. Wesker made no move to push him away, and after what felt like several minutes, Leon managed to break off with a gasp. He staggered back, breathing hard and eyes burning.

"Satisfied?" The wound healed before his eyes and Wesker rolled down his sleeves. To be honest, Leon was far from satisfied as he licked his lips while eyeing the blond. He wanted to drink more of the sweet crimson, could already feel himself building a dependency on the liquid. He managed a weak nod, trying to calm his breathing. He didn't have to look to know his own wounds had healed completely, leaving unscarred, flawless skin in their place. Everything except for his wings, which he stretched slightly and looked at under his arms. The feathers were still broken, mangled, or missing completely.

"I want to train more." Leon needed something to get his mind off of his newfound addiction. It would be a good excuse to stay close to Wesker and maybe try some of the moves he learned earlier. He didn't wait for the blond to reply before launching himself at Wesker and aiming a jab at him. Although his back was to Leon, Wesker was still faster and managed to dodge the attack with a graceful spin. Leon's punch went wide and he turned, attempting another and another. He watched Wesker's fighting style, analyzing it and putting it to memory. The blond almost never went on the offensive, saving his energy and only striking at Leon here or there when he had left himself open. It wasn't until Leon made a crucial mistake that Wesker would leash his full out assault, and Leon decided he wouldn't give the blond the chance. He had a new repertoire of attacks to test that Wesker wouldn't see coming, which he could use to his advantage and gain the upper hand by changing his fighting style drastically.

Leon continued his assault, not stopping for a moment. When Wesker side stepped a punch, he used the momentum to spin counter-clockwise and launch himself into the air, twisting his body and aiming a kick at Wesker's head. The blond easily dodged it, a smirk on his face as he watched Leon's changing combat style. He was impressed by how quickly the agent could learn and adapt.

He's almost ready.

Distracted by his own thoughts, Wesker left himself open for an attack. Leon took advantage of this, spinning in the air and sending a strong kick to the blond's chest, sending him across the room and into the wall. Wesker recovered almost instantly, his initial look of shock replaced with a smirk.

"Well done."

Leon looked smug but secretly enjoyed the praise. He straightened and flexed his muscles.

"Your skills with your hands and legs are strong, but there's a weapon you've neglected to use at your disposal."

Leon raised a brow. What could Wesker possibly mean?

"Your wings. They may be the strongest weapon you have. Any foe you face will not consider the potential of an attack with such range."

Leon flexed the large black plumes.

"Show me."