The people who came to back up X and Zero (and the others.):
Bass Reason for helping: Doesn't want X to die because he thinks X is the original Mega Man and as such he wants to be the only one to kill "Mega Man"
Crash Man Reason for Helping: Was sent by Dr. Wily to keep an eye on Zero. So happens that there is a large battle raging on.
Air Man Reason for Helping: Same as Crash Man.
Also no response from EVE to Zero who woke up and has dark red eyes, emitting a new energy signal, and has dark red armor instead of normal red colored armor?