Yes, the spell should be the second prize from the last (the last prize usually a Yellow Notebook), claim the spell first (in this case Avifors). After claiming it, open the Memory Book and activate another Duelling Event, let it sits while you're completing the 1st Duelling Event. After completing the 1st Duelling Event by then you can move to the 2nd Duelling Event you've activated.
Disclaimer: this worked for me more than a year ago, I don't know if this works now. Perhaps, JC has fixed this bug exploitation now, who knows.