'Chaos is power, power enriched by the heart.' Since he's suffering from amnesia and mind-control, he can't focus his powers as well as he could in SA2, so Shadow's state of mind influences the energy he draws from the Emeralds, and alters his powers, much like in Sonic Adventure, where Sonic and Chaos drew upon completely different 'sides' of the Emeralds' powers. It took me a while, but I finally realized that the Karma Meter in Shadow the Hedgehog is a perfect representation of how Chaos Energy works.He's using Chaos Control, the hero side Limit Break. Furthermore, directly after Sonic collapses, Shadow flies forward into the camera.He collapses, and Shadow is the only one left. What is much more likely is that Sonic has been fighting the Black Arms, but he's just not strong enough.

In fact Sonic is clearly bruised and battered, no cuts or bullet wounds, and Shadow's clearly not aiming at him. Some people suggest that Shadow has just shot Sonic, despite him not being in a position that really lends any weight to this. In the intro sequence, Sonic passes out in front of Shadow.Just as there was no way out of running into water in many Sonic games, for Shadow the more lucrative path is always high up and he has to confront his fear to get there. A total flip on Sonic's fear, which takes place in the depths.

So what is Shadow's fear? ACROPHOBIA, the fear of heights. The easiest way to die in Shadow's game is in falling to your death. On the other hand, he has fallen from space TWICE by now, and had horrible, horrible things happen to him high up in space. And fear is no use when you're being made into a living weapon.

But in Sonic games, water was a huge obstacle and became a canon fear for him.

One of the things people complain about most in the whole game is the way there's so many pits and you're so likely to die in them.

Black arms shadow the hedgehog