Armenian-American painter Vartan Malakian is a famous bearer of this name. It is also the middle name of his son, Daron, who is best noted for being a guitarist and second vocalist for System of A Down as well as being the frontman and lead guitarist of his own band, Scars on Broadway.
Actually, Vartan is the name of an important character in the very famous Armenian novel Khent (The Fool). He is the main hero of the story and lover of Lila, who he tries unsuccessfully to rescue. The novel`s influence on Armenian culture could be why it is so popular among Armenians today. They don`t mention his siblings, though.
Vartan could be great for a character name. The character could have a sister or partner character that also means rose or something of the like, Nasrin or Vardo for example.