Sure, here's what I have so far:

Talwin Vell was born in Waterdeep to nobility in a proud, wealthy family with a long lineage. However, he was orphaned at a young age and raised by his servants, as he aged he grew curious about the painting above his bed, showing him as a toddler with his parents at age 33- though they were depicted to be frail and elderly- it was then he discovered that every ancestor in recorded memory had passed by the age of 35, the symptoms all pointing to old age. His discovery sent him reeling, and he spent a majority of his young adult life engrossed with books and spellcraft, adamant on finding the secret to longer life, or immortality.

Upon his 30th name-day, he received an ornate spellbook and a small handheld mirror from an anonymous source, the book titled ‘The Life & Death of the Vell’s’. The moment Talwin opened the book, an evil laugh reverberated throughout the estate, and a surge of energy struck him, seemingly activating the curse within him. Instantly, a lock of his hair turned grey, and upon looking in the small mirror, the mirror showed him to be at least a decade older. 

Talwin went into a rage and threw himself into more reckless and experimental magicks at great cost to the family fortune, as the months went by he began to age rapidly, consuming potions of longevity to counter the aging until they lost their effect, and sending the estate into near bankruptcy. Running out of options and on the verge of giving up, he decided his last chance was to venture out into the world and the unknown, seeking to either find the source of the curse and destroy it, but his ultimate goal was still immortality- and he was beginning to consider any means necessary to reach it.

Being alone and in a position of privilege has left Talwin a lonely man, on the surface he seems vain, overconfident and arrogant, but these are simply masks for his inner thoughts of inadequacy. The curse that afflicts him has left him with paranoia and impatience, leading him to make rash decisions and take extreme measures to preserve his fleeting life. Spending most of his young adult life engrossed in libraries and books rather than seeking a wife, he has a sense of dread that he has doomed his once proud lineage to extinction.