u cant be a madrigal but u can pretend :)
You become a madrigal by completing Mission 10 on the 39 Clues site.
You can become a madrigal by finishing mission ten but to do that you have to have all 39 clues.
No you can't be a madrigal if you created an account on the 39 clues. Trust me I tried it once.
The branches in the 39 clues are Ekaterina, Janus, Lucian, Tomas and Madrigal
Grace=Madrigal Leader There is a Madrigal watcher
Grace = Madrigal Leader There is a Madrigal watcher
madrigal
Grace is a Madrigal.
madrigal
madrigal
madrigal
A branch desendant of Madeline Cahill