Kai was born to a small and little-known Arvek Nar clan whose only potential claim to fame is that several of its bloodline served (albeit with little distinction) as mercenaries in the fighting that finally freed Blar from the rule of the Crimson Templars. A child at the time, she grew up knowing Blar as a nation-state in its own right, and, on reaching adulthood, served for two years as an archer in the city's military forces. Despite doing well with the military structure, Kai wished to see more of the world, so when she mustered out, she spent a year as a mercenary, before the company dissolved with the death of its leader. With the dissolution of the mercenary company, Kai found herself in the city of Alexandria, seeking to start the next chapter of her life.
She spent some time in the city, working as an adventurer out of the famed Alexandrian Guild of Adventurers. She took part in a few good battles as a member of the Guild, including action in Rune at the conclusion of the war. It was on her way back to Alexandria that her life would undergo a drastic change, a result of her own choices.
Travelling alone, as was her wont, Kai was meandering, not taking a direct path back to Alexandria. As she crested a small hill on a lonely road, she came across a group of men who appeared to be bandits, just starting an attack on what appeared to be a two-wagon caravan of priestly nature. Excited by the prospect of action, she impulsively spurred her horse and charged into the fray, catching the bandits off-guard. Still, the bandit attack had left the caravan's four-man team of guards dead, as they'd given their lives to defend the priests and the cargo of one of the wagons. On impulse, Kai offered her services to the priests... who, lacking any other sort of warriors to guard them and their goods, accepted.
They travelled for weeks, ending up in an area completely unknown to Kai, amidst trees so tall she couldn't see the tops of them and with trunks so think that they were broader than the length of her lance. The priests performed a ritual at the base of one of the huge trees... and a doorway, with stairs leading downwards, appeared inside the tree itself. They asked Kai to carry a small chest down into the tree for them, while they carried their own things. Once in the tree, Kai found herself to be trapped, as the doorway at the top of the stairs closed behind her and the priests refused to open it, again.
The priests then explained that they were followers of Serriel and that they'd been entrusted as members of the Order of the Seal to hide away and protect an artifact of great power, to keep it safe from the forces of darkness -- who had certainly been behind the bandit attack Kai'd helped to turn aside. In order to fulfill their sworn duty, in order to keep the secret with which they'd been entrusted, they could not allow Kai to leave, as she knew the location of their secret stronghold.
Surprising the priests, Kai accepted this, agreeing that protecting such an artifact was too important. Kai also surprised herself, because she -meant- it; she wasn't just agreeing with them to get them to let down their guard to find a chance to escape. Time passed, and Kai ended up truly proving herself to the priests, who inducted her as a member of their Order. With her oath, the last words she spoke after that day, she swore to never speak again, lest she reveal (intentionally or not) the secret she'd come to know, the secret she'd vowed to protect to her dying breath.
More time passed, months, and the high priest of the group was granted a vision -- of Kai leaving the tree and returning to Alexandria, where her future lay. Having already proven herself and taken the vows, Kai was allowed to leave. At first, she didn't even wish to go, but the high priest made it clear that the vision he'd seen was from Serriel herself, and that, obviously, the goddess had greater plans for Kai than simply sitting in a sanctum hidden inside a tree. She was a warrior, and Serriel wanted the warrior to fight.
And so, a long time after the last time she'd been to the city, Kai returned to Alexandria, wearing the heraldry of Serriel, and still beholden to her Vow of Silence.
This character has taken a Vow of Silence. She does not speak, although she is clearly capable of doing so.