WARNING: The following contains spoilers for Maestro: War & Pax #3, by Peter David, Javier Pina, Jesus Aburtov & VC's Travis Lanham, on sale now.
While it has become the norm for a superhero to have dual identities, the Hulk always broke away from that mold by having several. Whether it was Bruce Banner, the Savage Hulk, or Joe Fixit there were always multiple facets to Banner's psyche that saw exploration, including one of his most evil personas, the Maestro. It seemed that the Maestro was a personality completely independent from all the others, but Maestro: War & Pax #3 seems to suggest that a Bruce Banner lurks within his mind after all.
When Maestro first appeared in the alternate future of Peter David and George Perez's Hulk: Future Imperfect miniseries in 1992, he was an expansion on the current Hulk of that era who stood out as a merged form of all of Bruce Banner's personalities. Reasoning that his fractured psychology could best be understood as different aspects to the scientist, the new Hulk was a healthy-minded hero with all of his strength and smarts. Maestro appeared to not only share the same amalgamated mind but to present an evil, twisted version of it.
In almost all appearances of Maestro, his identification as Bruce Banner seemed nonexistent and he almost never reverted to his human form. The egomaniacal villain would be unlikely to expose such a weakness of himself openly, and yet that is exactly what the demigod supergroup known as the Pantheon seeks to get him to do in his latest series. The knock the despot unconscious and storing him in a cell where he is hooked up to a telepathic machine they hope to convince Maestro to turn back into Banner so that they can finally put an end to his reign and kill him at last.
Throughout the process Maestro resists, and though they keep referring to him as "Doctor Banner" he continues to correct them, informing them again and again that he no longer goes by that name. Where the telepathic assault gains a foothold is in Maestro's traumatic memories of his own childhood in which his father murdered his mother while he watched, a helpless child exposed to a traumatic memory that would forever scar him. Despite Maestro's seeming sociopathy throughout much of the series, reliving the traumatic memory does seem to deeply disturb him. In fact, it disturbs him so deeply that he seemingly breaks out of the telepathic prison and murders many of the Pantheon members.
In the midst of his rage-fueled attack, he sees a vision of his mother horrified at what he's become. In order to appease her, he reverts back to Bruce Banner, now a fragile old man with a long white beard. Mere moments later he is shot, and the Pantheon gather around his corpse, still unsure of their victory. It turns out that his entire resistance was part of their plan to lead him into a false sense of security, and the moment stands out as a major character revelation regarding Maestro that confirms that a piece of Banner lived within the villain.
This has considerable implications for who Maestro really is and what he may become. Through so much of his initial appearance and subsequent adventures menacing Marvel's heroes past and future, he delighted in his power and the violence he could cause with psychotic glee. Seeing a human side to him comes as a revelation that adds considerable depth to the character.
With two more issues of the series remaining, it is all but certain that Maestro will somehow survive his current ordeal. This could very well be a ruse on the villain's part, and he may have only feigned the survival of Banner's psyche as a small piece to a grander plan. Although he is seemingly dead for moment, the Pantheon currently seeks a more "permanent" solution, indicating that they are aware that Maestro has some means of coming back and possibly gaining the upper hand upon his return.