(Quiet, shy, a perfect wolf would be a bit more outgoing... More courageous.)
(Those are not flaws...
Here are some flaws
Arrogant (Dylan)
Vain
Controlling Freak (Dylan)
Letting people walk all over him/her (Yuki)
Two faced
Selfishness
Greedy (Dylan)
Hero-Complex
Ignorance
Too kind, (Cares about the enemy and thinks that everyone is good) (Yuki)
Naïve
These are only a few, Clumsiness is not a flaw)