I've been really interested in Eyenon fusion since Blackmagic purchased the software and made it available for free.  I'm a bit of a Blackmagic fan boy, and I'm finding the power that Fusion contains to be very intriguing.  Oh yea, it's free too. 

Here is a video tutorial of Eyeon's masking, something that's missing from Blackmagic's official tutorials. Coming from the After Effects camp, this is the first thing I want to understand about Fusion.