The trick here is very simple. Here is a video of the strategy to use.
http://www.youtube.com/watch?v=fMmIb...ature=youtu.be
Please look carefully at the orbs positioning.
Here is the correct link for the video. Dont know why the link is always cut.
http://www.youtube.com/watch?v=fMmIb2s8xkg&feature=youtu.be
I don't get the guy's strategy in picking who to kill first. He should be targeting the odd mask type out of the group since if it gets a second chance to attack it actually has a chance to matching attack timings with another mask. The orb storage for the next level is pretty nice though.