While we're on topic of Plague Engineer, there's a neat little combo that Yavimaya enables:

Step 1: Use Yavimaya to turn all lands into Forests.
Step 2: Use Life and Limb to turn all Forests into Saprolings.
Step 3: Use Plague Engineer set on Saprolings to perma-delete all your opponents' lands forever.

Quote Originally Posted by rufus View Post
If you have 2x Harmonic Prodigy in play and the ability of another shaman you control triggers, does it go infinite?
Why would it? Sounds like 2x +1.