Hailing from a remote corner of the Western Isles, where the old Fae lands are still remembered and embraced, the warlock later known as Glaw Trwm had an affinity for exploration and fighting, saved only by a silver tongue. Having originally been something of a brutish, bullying outlaw who bribed, tricked, lied or otherwise threatened his way into the employment of a merchant company from the Western Isles. Despite his unsavoury nature, he eventually proved to be a fairly competent officer. After several years of this, however, his luck turned bad. A great storm rocked his airship during transport and though he was able to get his command below decks in time to avoid the worst of it, Glaw himself was caught and tossed overboard; his heavy armour preventing him from using his natural wings.
In the depths, he pleaded to the seas for a second chance, a way to earn his life again. He offered gold, blood and even his own soul just so he wouldn't drown like a rat knocked from its ship. To his delight and horror, Sionnaine took notice and a pact was struck. She did not claim his soul, instead taking his mind, remoulding it to her fancy, and leaving the Sprite with a single cup of tarnished gold large enough for him to lay in.
It carried his delirious form to his home shores where the Lady of the Waves thought he may be useful, and left a mark. Sionnaine took all that he once was as payment for his life, along with his new name carved onto his very soul, and shifting companions of both the physical and ethereal seas; both as eternal companions and permanent reminders that he used to be something different, something displeasing to his patron.
And that he owed her a debt.
For some years he wandered the coasts and waterways of the Western Isles, purposeless and alone. Over time his power grew and his wanderings found him a reputation, not as a Sprite or other Fae, but as a herald. Over the years it became a common superstition amongst the coastal villages that a wandering soul from the depths would foreshadow destruction and death to the deserving and monstrous, bringing forth creatures of the deep to smite and punish like a contained storm. One day, after many years, the Sprite now known as the Trailing Storm stumbled across a strange site. A strange warrior whose scaled form called forth snippets of memory long since forgotten. The Chameleon warrior introduced himself as Qau the Mighty, a warrior from beyond the Great Portal who had arrived to explore. He wore a Ring of Plentiful Water that showed clearly its makers were of the Isles, and his stories and demeanour were enough to convince Glaw of his good intensions and allowed Glaw a chance of self-reflection. Encouraged by this, Glaw decided that his decades of purposeless wandering had to end, that there was far more to the world and an almost instinctual desire to explore began to burn, unknowingly reignited after being doused by the cold ocean depths. When Qau offered Glaw a chance to join him on his journey back through the portal, he could hardly refuse. Now he and his new companions head for the fortress city of Balla, and once more a storm trails behind them.
Following the battle against the Fallen Angel, Glaw lost his leg below the knee and now has a prosthetic leg made out of a crab leg. Despite its odd crusty appearance, it does function normally.