Vecna is the main antagonist of Stranger Things and his backstory will likely hold the key to concluding the series. Before turning into Vecna, he was known as Henry Creel, a sensitive kid. But as the events unfolded in season 4, he turned evil. A new theory has emerged that gives us insights into his change of heart.

Henry Creel moved to Hawkins with his family in 1959. As a kid, he discovered that he had supernatural powers and could manipulate the perceptions of others. Using his powers, he killed his mother Virginia Creel and sister Alice Creel. Later he was taken to Hawkins Lab by Dr. Brenner for further studies and was designated 001.

The question is, what drove Henry Creel to madness? This new theory might provide the answer, so let's dive into it.

A Stranger Things Play is arriving soon which will explore Henry Creel's backstory. When the cast of the play was announced, Henry Creel was paired opposite Patty Newby (Bob Newby's sister). It was an odd choice and quickly caught the attention of viewers.

Patty Newby is a new character introduced in the play as she is entirely absent from the original series. Notably, it has come to light that her father served as a pastor known as Father Newby. As recounted by Victor Creel, they called a priest to perform an exorcism on the house, an act that upset the demons. The exorcist was probably none other than Patty and Bob's father. This marked the inception of a connection between the Creel and Newby families.

Consequently, it is plausible that Henry and Patty were friends, and perhaps even romantic interests. There might have been an event that caused a rift between them, possibly related to Patty's father, who disapproved of their relationship. Patty is not mentioned by her brother Bob in the show, suggesting a potential tragic fate.

The separation from Patty could have deeply affected Henry, leading him down a path of becoming a mass murderer and harboring a profound hatred for humanity. When Henry instructed Eleven to focus on a sad/angry memory, it might be linked to his memories of Patty.

Another possible scenario is that Joyce, Hopper, and Bob tried to keep Patty away from Henry because they found him weird. It might have resulted in something tragic that motivated Henry to turn evil. That's why he purposely attacked Joyce's son Will and killed Bob. This checks out with some parts of another theory that Henry Creel rewrote time in 1959 causing Joyce, Hopper, and Bob to go to different paths.

Henry might have a personal grudge against the Newby family. In season 2, Bob revealed to Will Byers that he was having nightmares as a kid. He also said that one night those nightmares just stopped. It is possible that it was Henry who was responsible for the nightmares. They stopped when he was taken away by Dr. Brenner. But when he finally got the chance, he killed Bob.

Irrespective of whether this theory proves to be true or not, Patty Newby is likely to have a significant role in Henry Creel's journey. Something definitely happened to her which might hold a key to understanding Henry's motives.

The Stranger Things Play will reveal the history of Henry, bringing forth vital revelations. It has been confirmed that the play will have clues to season 5, making it essential to catch it prior to the final season to fully understand the lore. Regardless of whatever happens, it will be interesting to witness the dynamics between the young versions of Joyce, Hopper, and Bob as they engage with Henry Creel.