Born to a family cursed by the gods, Xavier was born a fox morph in a world slowly being abandoned by the gods. However, the nature deity Abrorita prevented his parents from harming him.
She was not able to stop a bandit raid on his home from killing them. However, when they tried to harm him, the ground itself tore them asunder. On his own and alone, the boy was found to be able to commune with nature well and he lived off the land for about 20 years.
By that time, the world had been abandoned by the gods, and mankind had been left to their own devices... and it began to slowly kill itself off. The God of Judgement, known as the Raven, approached the now young man with a proposition: serve him as a harbinger of justice, a Hunter. (Think Greek Furies)
To help him in his journey in bringing the ill of humanity to face their crimes, the Raven put inside of Xavier a fire elemental that had been held prisoner by the gods for centuries.
There's a reason they call that area the Black Forest now.
Over the next 200 years, given immortality by the Raven, Xavier built up a clan of 25 Hunters and proceeded to hunt around the world.
Xavier has been a fire mage for so long, it is like breathing to him. He has full control of his fire, and is able to make it burn to such a temperature that an opponent would be burnt to ashes. He can also imbue it into his sword, Molten Steel, to heat it to such a point it will melt anything in it's path save for pure stone.
Agent of Chronos: During a crisis to save his world, the fox failed, and the world fell apart. He was given another chance by the short and irritable god named Chronos, and now serves as his essentially field agent, doing work for him in other worlds. Being such grants him a portal ability to go into other dimensions with ease, though he must limit the time he is in there.
Molten Steel: A sword heated so hot, the blade is nearly liquid yet retains it's shape. The sword is able to be thrown and exploded, reformed via the fox's own magic- though he must be uninterrupted during that time.
Xavier was a member of the hunters of sin, a group formed that served the god of justice at the time known simply as 'the raven'. He served faithfully for 400 years dealing with a blight his own god created without his knowing but eventually began to travel other worlds. In one such world, he met who would become his future adopted son, Daniel Thyme as well as became the originator of his love interest, Tenta. After witnessing the boy's unusual trait of HOPE, he brought the boy back to Ivalice to try and rectify things... but, this inevitably broke things worse when major events were influenced by things that should not be there. Forced to RESET the fate of his world, he turned to saving his clan before they could fall to the raven's machinations and became servant to the god of time, Chronos. Now he diligently looks after the world of Ivalice, guides the new god of justice known as Efram and helps his son try to correct the mistakes caused in other worlds by 'those who have control'. He also acts as advisor to the clan, having relinquished his title as leader to better focus on raising his son and pursuing his own matters.
This fox is a bit of a quiet person, but the right topic or the right people will make him open up. He is overly protective of his son, to the point he worries constantly about his safety due to the fact he once linked minds with Daniel and saw the torture he went through, vowing never to let that happen again. His son is not the only thing he's protective of- his clan is one too. He viewed them as family, broke up many an argument and settled disputes for 400 years, and has become rather well at mediating grudges (though that may have just been dumb luck). He is also a very emotional person- his fire is linked with such, and he can become literally hotheaded if he gets too angry.
The clan had resigned themselves to celibacy due to their sterilization from the Blight's affects, but when an Amalgamate attempted to convert him, the beast inadverdently gave him the love of his life. It is an odd thing for him- love for love's sake, not love for "we lived together like a family for 400 years, fought together, mourned together, etc" sake. He's still new to it, and learning everyday. He can't leave her though- she's half his heart, one of his lungs and his left eye now.