First, it was Takuya and Aries... Then, it was Dante....
Now here comes a sketch of Avery - The Raikou Splice. Guess I'm on a roll. Anyways, Bio time!

In Pokemon: Synthesis, Avery is 17 years old, making him one of the youngest Splices alongside Kasi. He's one of the most extreme splices when it comes to emotions, as he feels very deeply, along with being short-tempered and can fly off the handle easily. This also makes it very difficult for him to control and restrain his electric energy abilities he gained from Raikou's DNA.

When Avery first awoke in Team Midnight's genetics lab in Sinnoh alongside Kasi and Takuya after being spliced, he immediately freaked out on seeing his transformation. Furious and enraged, he broke out of the containment cell he, Kasi, and Takuya were sharing and attacked the scientists. As security tried to sedate and contain him, he only became more embroiled in his fury, the rage building up along with his power until it reached critical mass. He was unable to control the electrical energy building up around his body, and it detonated into an explosive corona which destroyed the facility. He lost consciousness afterwards, and Takuya was forced to dig him and Kasi out of the lab's rubble.

Avery is a very introverted, shy, individual. In most cases he will not speak to others unless they take the initiative and start conversation. The only anomaly to this rule is when he is angered. Then he adopts a very blunt and direct attitude, and will tell off anyone who has bothered or wronged him along with making his opinion solidly known, with Kasi seemingly being the only exception since he has deep-rooted feelings for her that have built up over the years as they traveled together, which includes the passion of love.

Even before he was spliced, Avery was a troubled person. It is very difficult for him to trust others he does not know, and being pursued by Team Midnight only makes this worse, almost to the point of paranoia. This shows after He, Kasi and Takuya are discovered by Ash Ketchum and Tyler Sapphire, who intervene in a fight between them and a group of Team Midnight mercenaries. When Tyler began his approach to try and help after the mercenaries were driven off, Avery immediately started charging his electrical energy, and needed to be talked down from attacking Tyler, who reassured Avery and the other Splices he and Ash meant no harm.

As for his relationship with Kasi, Avery's love for her is true and pure all the way down to his core. He eventually is able to work up enough courage to confess his love for her, and she accepts him. He will do anything to keep Kasi safe from harm. The same is true with Takuya, as Avery thinks of him more like a brother than a friend. This is prominently shown when Avery is forced to fight Takuya when he is brainwashed by Team Midnight, as when the battle ends, Avery ends up holding a dying Takuya in his arms and starts to cry as there is nothing he can do until Dante, another splice appears. Along with his strength and speed granted from Raikou's DNA, Avery also is adept in martial arts as he earned a brownbelt in Karate prior to being spliced.

Memorable Quotes:
"I am not some Pokemon that you caught to breed, and I sure as hell am not your guinea pig!"
"“We ‘were’ people. Those hunters that were chasing us… Their working for some sick scientists that did this to us. We escaped from a lab they were operating and have been on the run ever since.”
“Is that all we are to you? Just some experiment for your disgusting, ill-gotten gains?!”
"I want to remain with you, now and always. I want to be by your side for the rest of my days… Kasi Martens, I love you.”