The MCU established early on that no normal living being can use the full power of all six Infinity Stones without suffering serious and permanent physical damage. 👀🫰
However, in Avengers: Endgame, many fans wonder why Tony Stark seemed to react differently compared to Thanos and Hulk.
When Smart Hulk used the Nano Gauntlet to bring everyone back after the Blip, his body was immediately hit by huge amounts of cosmic and gamma radiation. Thanos also struggled with the intense power and physical pain caused by using the Infinity Stones. Even with their superhuman bodies, the Stones caused them extreme and visible suffering.
Tony’s situation was different because he only had a few seconds. His Mark LXXXV nano-suit briefly helped control and direct the Stones' energy to his hand so he could perform one final snap. The suit absorbed some of the initial energy, giving him just enough time to say his final words.
But that did not mean Tony escaped the consequences. The power of all six Infinity Stones was still too much for his human body, and it quickly killed him. His calm final moments were not because the Stones caused him less damage, but because of his incredible willpower as he used his last seconds to save everyone.