As a type 1 vampire, Michael had bloodred eyes and stony, unnaturally white skin which shines in light. He also had beauty, but his was very masculine and slightly diminished by his usual arrogance and aggression. He was tall, muscular and well-built, and had dark brown hair which was shorn short.
Michael's main personality trait was his arrogance, as he believed very strongly in himself and usually believed he'd be better at something than another person would. He was stubborn and insistant, and very rarely did he back down.
Michael's last known home was a squalid, small house located in a suburb of Otsu. He didn't spend much time there. The house was completely destroyed in the explosion which killed him.
Michael did not have an unique supernatural ability of his own, but he all of the abilities which all Type 1 vampires have. They included supernatural speed, strength and senses, as well as longevity and the ability to turn others via his venom. He could also heal himself using his venom, and his stony skin was impentrable to anything except vampire teeth, werecreature teeth and Hunter weapons.
- Father - Andrew Firelock (deceased)
- Mother - Eleri Firelock (deceased)
- Brothers - James Firelock, Osian Firelock, Gwion Firelock, Sean Firelock (all deceased)
- Twin brother - Robert Firelock
- Sisters - Tannith Reddan, Lleucu Grey
- Unnamed wife and children (deceased)
- Brothers in law - Tomas Reddan, Seth Grey
- Nephews - Tavis Best, Rajan, Matthew, Chris, Aidan, Riley and Jensen Firelock-Reddan, Harrison and Ethan Grey
- Nieces - Pippa, Charlotte, Nyasia, Lyla, Hope, Mackenzie, Gracie, Darcie, Cate, Eboni, Alivia, Becca and Sofia Firelock-Reddan, Alessia Grey
- Great nephew - Braedan Bennet
Like the rest of his family, Michael grew up in a small town in Western Ireland and in the middle of a civil war. He and Robert both joined the fighting when they were 13. Throughout their adult human lives, Michael had been jealous and opposing of Tannith, hating the fact that she was so obviously their father's favourite and had been named as heir. Michael disagreed with that, sure he would be a better future leader since he was adult and male.
Michael had been fighting alongside Robert and Tomas the day the 3 supposedly died, but had been separated from the other 2 during the battle. He was fatally injured and left to die, but afterwards found and turned by an unknown type 1 vampire. He never saw that vampire again. He lived through the next 5 centuries, killing for blood and getting into several skirmishes. When he heard that Tannith Firelock was their new world leader, he travelled to Otsu to meet her, and demanded she yield that power and responsibility to him. However, she declined.
A few days later, he was confronted by Robert, who'd been informed by Tannith of their earlier confrontation, and had chosen to interfere. The twins fought and Robert was victorious, due to the use of Hunter knives and the element of suprise. However, Robert spared his brother, and this led to Michael attacking Tannith and accidentally killing Lleucu. Horrified, Michael fled. But Robert trailed him back to his home, and attacked him, intending to kill him to avenge Lleucu. Robert succeeded in killing his twin, but also died in the attack, since he'd had to blow up the house in order to prevent Michael from reforming, and he himself was too badly injured to escape from it in time. Robert was later saved when Tannith recreated him.
Michael is a Hebrew name which means "who is like God?". This could refer to the Godlike complex he'd developed by the end of his life. His middle name, Boyd, means "yellow-gold". His surname may mean "firearm" or "fire forge", and could refer to the family's martial history or the fights and battles he became involved in personally.