The Welsh fighter will return to Oktagon next week, but outside the cage, Aby has already fought two greater challenges: overcoming stage three cancer and coping with cystic fibrosis.
Aby was diagnosed with cystic fibrosis, an inherited disorder that predominantly affects the lungs and digestive system when he was just two weeks old.
He had initially planned to be a footballer, and as a talented teenager represented Wales U13 through to U17 level, playing alongside Gareth Bale, Aaron Ramsey and Joe Allen - but kept his condition a secret.
Training at Wrexham during the day, Aby would spend the evenings at the gym, taking part in classes run by his uncle Julian for people with cystic fibrosis.
It was at the gym where his love of mixed martial arts kicked in.
"My uncle got me started MMA as he used to train, and he started taking a class with the proceeds going to cystic fibrosis," he told Flashscore.
"So I started training with him and I fell in love with it."
Aby initially trained twice a week, but this gradually increased to three, and then four nights a week. Eventually, his desire for amateur bouts took over his football ambitions.
"I was fortunate to be around people with a professional attitude and approach from a very young age," he said. "This helped me with my game in mixed martial arts."
"Cystic fibrosis has taught me a lot about fighting, and fighting has helped me with cystic fibrosis.
"Life is a fight, so what better way than to fight for a job? It is something I love."
Aby was later diagnosed with stage three testicular cancer, and after intense chemotherapy received the all-clear in March 2019.
Remarkably he returned to the Oktagon MMA promotion - which makes its UK debut in Manchester on November 4th - just eight months later.
"The battles I have experienced outside of the cage have taught me many lessons. I feel like this opportunity (in Manchester) has taught me about being persistent, committed and never giving up."
By climbing up the rankings and taking on Garcia for the world title, what does he think of the success of his former club Wrexham who have made a stirring comeback into the football league?
"It’s fantastic for the town," he said.
"The community deserve it they have stuck through the club through the dark times and deserve this moment.
"It’s a similar story to mine. I’m proud to be from Wrexham and represent its people.
"All I’m focused on is becoming world champion."