Assassins Creed Brotherhood : Courtesans Guild Challenge 3+BONUS glitch

How to complete the Courtesans Guild Challenge that you need “20 Enemies stationed at Guard Posts killed using the crossbow without being detected”.

The easiest way is to do it while you are at Sequence 6 (the mission with Barolomeo) because there are several guard posts there.
First travel through the tunnel to Terme di Diocleziano. Go straigh, then turn right after the arc and shoot the brute from behind the tree!
Repeat it until you are done 🙂

Also, a bonus video by me, of a group of guards that cannot be killed!!

Played and composed by me.
All rights of the game belong to ubisoft.
The music is from inside the game and belongs to its righteous creator and owner, Jesper Kyd.