Yoku can posses people but sometimes he can only control the body and not the mind. Neo Shadow is one of the fer people he can't fully control but once linked with N.S. they both unleash an incredible power.
I can imagine them doing one fatal punch ._.
How did you know?!?!?!?!
/._./ IDK. Lucky guess i think XD
The Punch is actually a reference to Chris Redfield's Haymaker from Resident Evil 5 (He has gives out one heck of a Haymaker O_O).