Why I Don't Think Neither Serges nor Isoc is Dr. Wily
There are theories that Dr. Wily is still around in the Megaman X series but I just stared to think, neither Isoc nor Serges is Dr. Wily. Certainly Dr. Wily's influence has lived on in the Maverick Virus but most likely not him. But I had theories that could counter the idea that both Serges and Isoc is Dr. Wily.
For Serges, he's not really all that played. Sure Serges does have Dr. Wily's appearance but it doesn't mean he is Dr. Wily. Maybe he, Serges and Violen were Dr. Wily's creations who were obsessed with assembling Zero. Maybe years later, Sigma found these three robots and activated them. It seemed that they obsessed with Zero as some kind of "savior", and that these three were created to serve Zero in the place of the late Dr. Wily. Also, I thought Serges despite being the leader of the X-Hunters, he is not the second to the last boss neither does he use a skull-shaped battle tank to fight Megaman X. He talks more about "fulfilling the prophecy about Zero" which for me is a hint, Zero was supposed to succeed Dr. Wily.
Another is Isoc, a SUBORDINATE of Gate and Dr. Wily is not willing to take that job. Okay he is voiced by Takeshi Aono but that is NOT enough for him to be Dr. Wily. It's possible that he has Dr. Wily's memories or influence, maybe in the process Dr. Wily also created Isoc and Gate activated him in his era or three, he ended up having Dr. Wily's influence from analyzing Zero inside out, he soon got the data he needed. Dr. Wily's influence may have lived in Isoc. He may have been obsessed with Zero and hated Megaman X, because of some kind of influence. He could have just been obsessed with Zero because he found the robot to be so powerful. It's possible that he also ended up getting some of Dr. Wily's replicated memories in the process. So far, nothing much suggests that he is Dr. Wily but it's suggestible that he is at least, a result of Dr. Wily's posthumous influence. As for the "??" character saying, "Go Zero, you're the strongest robot." might just be Zero's subconscious, considering Dr. Wily had actually implanted much of his plans into Zero's head.