Jade's Brother.

[Chill Ass Demoman]

Jade the Vampire hunter's bio states she's looking for her brother, any idea who it may be or if he's even in the game?

[aSmolGoth]

Just seems to be the character's thing. She's also in their other game with pretty much the same motivation.

[ToeSama]

Her profile also mentions she's of a noble house. Vincent's profile mentions a banished sister. Magnus' profile mentions an exiled daughter. I get the idea the three are family. It makes Jade (the supposed problem child of the house) an interesting reflection for using Chaos flame magic, where Vincent and Magnus use Frost magic. That said, even if this theory is right, we can't be sure Vincent is the brother who went missing. It might be a younger, less capable sibling. Likely so, in fact, since Jade and Vincent's paths can cross.

[Alchosin]

Originally posted by ToeSama:

Vincent's profile mentions a banished sister. Magnus' profile mentions an exiled daughter.

The person both of these characters are referring to is one of the few bosses you kill early in the game, which also have their family's signature ice power.
Keely the Frost Archer.

[ToeSama]

Keely's profile mentions time in the militia, but nothing of family ties. It's certainly quite possible, but there's more conjecture for it being otherwise based on profile blurbs alone. Is there confirmation of this somewhere?

[Dragonfang]

My guess is its Tristan the Vampire Hunter. Both Jade and Tristan wear almost the same apparel and both are practically armed to the teeth. Plus Tristan is a lot weaker than Jade which in my mind says Jade is Tristan's older sister