Possess 5 different guards without touching the ground.
― In-game description[src]
"Guard Swappin'" is the fifth Master Thief Challenge in "Rumble Down Under" of Sly 3: Honor Among Thieves. It is a variation of "Unleash the Guru," where the the Guru must possess at least five different guards before landing on the ground again. The challenge does not start until after you possess a guard, so you can touch the ground as long as you have yet to possess a guard.
Video[]
Sly 3 Honor Among Thieves - Master Thief Challenge - Guard Swappin'