Leap of Faith is an event randomly found in Pandemonium Fortress Level 1 in Act V of Diablo III. It may be nominated a bounty.
It is very short: approaching or touching a Cursed Chest will spawn several dozens of Winged Assassins (in waves, not all at once) and, after killing them, ultimately Sorenae, but surrounding Reapers may join the fight as well.
Killing the unique Reaper ends the event and cleanses the chest.
Video[]
Diablo 3 RoS - Leap of Faith Event - Act 5