Warning: The following contains SPOILERS for The Flash season 8.
A new theory suggests that the time virus at the heart of one storyline in The Flash could transform Iris West-Allen into a villain. If true, this theory could force Barry Allen to face his greatest struggle ever, pressing the Paragon of Love to sacrifice the love of his life for the good of the Arrowverse. This would also be an ironic echo to the end of the Armageddon event that opened The Flash season 8, where Barry refused to make a similar decision regarding the death of his worst enemy.
The strange time sickness which plagued Iris previously only caused her to experience lost time, hallucinations of alternate timelines, and uneasy feelings. Shockingly, the disease progressed to the point that it began disintegrating objects around Iris, without her being aware of it. This culminated in Iris accidentally erasing Renee Wazzo from reality, shortly after reuniting the woman with her long-lost daughter Tinya.
It's possible that the objects and people seemingly destroyed by Iris and her time sickness still exist somewhere and might be restored. However, Iris still remains a danger to herself and others and it is possible that the shock of what has happened could push her over the edge, like many other Central City metahumans who were corrupted by their powers. While this chain of events may seem unlikely, it would make for an interesting and unexpected finale to The Flash season 8.
How Iris's Time Sickness Works
Iris' time sickness was introduced in The Flash season 7, episode 16, "P.O.W.," at the height of the Godspeed War story arc. In the middle of the fighting, Barry Allen was briefly taken out of time by Deon Owens, the avatar of the Still Force, who explained that he had sensed something causing Iris West-Allen to begin phasing through the temporal planes, moving in and out of the timeline at random. It took all the power Deon had to keep Iris set in a single time period with him, due to the damage being inflicted on the timeline by the Godspeed War. Thankfully once the fighting was over, Deon was able to use his powers to stabilize Iris enough that she could live a normal life with regular treatments, though he still had no idea what was causing her illness.
Iris' condition began to deteriorate following The Flash season 8 Armageddon event when Iris began investigating the death of her father, Joe West. Discovering evidence of timeline manipulation, Iris asked Deon to undo his treatment so she could use her time sensitivity to find proof that someone had changed history so that her father died. Deon obliged her, leading to the discovery that the Reverse-Flash had used the Negative Still Force to change the timeline. Unfortunately, due to Barry Allen restoring history to what it should have been in the final chapter of the Armageddon event, neither Iris nor Deon remembered that they had reversed Iris' treatments and Iris' condition worsened as a result.
Eventually, Deon determined that he had been treating Iris' illness in the wrong way, presuming that the temporal mutations spawning around Iris were like the symptoms of a virus. The truth was that Iris herself was the cause of the corruption and her presence in the timestream was the cause of the timeline fracturing around her. The events of the episode "Reckless" confirmed that Iris' presence was slowly unmaking reality, causing all the furniture in one waiting room to disappear after she had spent several minutes standing in it. The final straw came in the finale of "Reckless' when Iris had a seizure and caused Renee Wazzo, a woman who tried to comfort her, to disappear in a cloud of green particles similar to the Thanos snap from Avengers: Infinity War.
Why Iris Would Work As An Unintentional Villain
A good villain must challenge their hero, but there is very little that challenges Barry Allen after eight seasons of The Flash. Rather than create an endless horde of slightly more powerful villains for the hero to outwit or beat up, good superhero writers instead find ways to test their heroes with ethical challenges their powers and training cannot easily overcome. There is why the most powerful superheroes are often tested in a moral arena, avoiding the temptation to abuse their powers or facing emotional battles where all their power is effectively useless.
For all the ways that Iris West-Allen is the source of Barry Allen's moral strength, she is also his greatest weakness. For all his righteousness, Barry has never been particularly good at keeping his emotions in check or thinking clearly when Iris was endangered, as shown in the events of The Flash season 8 Armageddon event. It is easy to believe that losing Iris, whether it is through corruption or Iris simply being driven mad by her condition, could break Barry's spirit completely. If nothing else, it would be the ultimate test of their belief that their love can overcome anything.
How Iris Would Be A Callback to Armageddon
Beyond being a challenge Barry Allen couldn't run his way around, Iris West-Allen being revealed as the final villain of The Flash season 8 would also be a dark callback to the finale of the Armageddon event. Facing the threat of being erased from reality, the Reverse-Flash pushed Barry, the rest of Team Flash and the Green Arrow of the future, Mia Queen, to find a way to save him, even as he taunted them with the knowledge that he would never stop trying to destroy Barry Allen and everything he loved and valued. Rather than allow Eobard Thawne to fade out of existence, Barry depowered his archenemy instead of killing him or allowing him to die.
Stopping the Reverse-Flash once and for all was a challenge for Barry on a physical and ethical level, begging the question of how The Flash season 8 could possibly top that moment. The answer is simple, yet sickening, and yet entirely logical from a writer's viewpoint. Barry Allen may have the moral strength to avoid killing his worst enemy because of his belief in the sanctity of life, even a twisted life like that of the Reverse-Flash, Eobard Thawne. Would he be able to show the same fortitude when faced with the possibility that the woman he loved more than life itself might destroy the timeline? It is an intriguing question and one that might lead to an epic finale for The Flash season 8 should this theory about Iris West-Allen becoming a villain be true.
The Flash releases new episodes Wednesdays on the CW.