Hmm, I like it but I don't really see it as a big flaw. Bane is
-The user is highly susceptible to a certain factor. For instance warewolves are vulnerable to silver, vampires to sunlight etc. The user of this flaw is weakened or hurt severely by something that is common to the world. It has to be something that is in abundance and used in everyday life or always around. This cannot be counteracted.
Maybe you could have the same flaw as Nameless because of the connection, but just having the connection that if Nameless gets hurt, you get hurt, doesn't really feel like a viable flaw for the system, and instead more of a solid plot device.