Thanos only needed the Power Stone to disintegrate half of life in the universe according to Avengers: Infinity War VFX supervisor Dan DeLeeuw. Despite getting help from the Guardians of the Galaxy, Black Panther, and the people of Wakanda, as well as other self-operating heroes, the Earth's Mightiest Heroes suffered their first real defeat at the hands of the Mad Titan, failing to stop the villain's plan to balance the universe by mass murder. By the end of the film, the world was in shambles, with people suddenly fading into dust, including some of the MCU's most beloved heroes.

Not much is known about how this predicament will get resolved in next year's Avengers 4. Directors Joe and Anthony Russo, as well as the cast, are scheduled for reshoots that will last the summer, while Marvel Studios remains mum about the film, so much so that they still won't reveal its official title. But between leaked set photos and comments from people involved in the project, it seems like time-travel and the Quantum Realm will both be significant factors in the narrative.

In an interview with Inverse, DeLeeuw talked about the creative process behind achieving the dusted off effect on people who were affected by Thanos' snap in Infinity War. As it turns out, it was only “the Power Stone [that] was blipping them out of existence,” and not a combination of several stones. “All the Infinity Stones have their signature color and appearance as a visual effect. So the ‘blip out,’ we thought, ‘What would all the stones do to a person, blipping them out?’,” he explained.

Before settling on the Power Stone, DeLeeuw and his team also thought about using either the Reality or the Soul Stone (and even both) to explain the idea on the dead heroes were being disintegrated into dust. But, while both were acceptable choices, they settled on the Power Stone because the explanation on how it could vaporize both life and non-life forms is much simpler to understand.

“We had concept art combining all those things, and it was getting too busy. It became too complicated. It was stepping on what the actors were doing. So it became ‘body turns to ash.’ We peeled away all those layers and focused on that one [Power Stone], deciding how quickly it would consume someone, what pattern it would consume them.”

Looking back at the effects of holding the Power Stone with bare hands in Guardians of the Galaxy, there's definitely a similarity to how the people disintegrated into dust by the end of Infinity War. Although in the James Gunn-directed movie, it looked more like the Star-Lord was decaying with patches of his face peeling off instead of pieces of him getting blown by the wind as seen in Avengers 3. DeLeeuw and his team also considered evaporating the "nimbus of energy or soul that is left behind" in the sequence, but in the end, they decided on using ashes. Based on the viewers' reactions upon seeing the film's end scene for the first time, it was effective.

Having said all of this, it's important to note that DeLeeuw's comments don't technically mean that it's also the case narrative-wise. Thanos needed all six stones to execute his mission, the VFX team only used the Power Stone as the point of reference when they were deciding on what effect they wanted to use to illustrate how people were impacted by the snap for better storytelling.