Avengers: Infinity War seems to have many fans seem to be hanging on to a rumor — the return of Quicksilver. Though the character died in Avengers: Age Of Ultron when Ultron shot at the Avengers, nearly killing Hawkeye and a injured child in his arms right before Quicksilver ran in front of them, taking the hit instead.
It was made obvious in the film that Quicksilver was dead, not to mention that both Marvel Studios president Kevin Feige and Age Of Ultron director Joss Whedon confirmed it. However, neither Kevin Feige or Joss Whedon said that he would stay dead, only confirming that he wouldn't be returning in the "near future."
Most people came to the automatic assumption that Marvel Studios couldn't keep a character dead, but while 10 years of movies seems like a long time to develop a character and a story, all that we have seen so far could be covered in less than a year of comics. Killing off characters in such early stages is most likely not on the agenda, especially since the major #InfinityWar is right around the corner. So here's why they killed him:
It's the same reason why the DC Extended Universe (DCEU) "killed" off Superman in his second movie; it's a different and interesting way to bring attention to a character. His sacrifice causes audiences to emotionally relate to the character and want him to return, which is the same thing the DCEU did with Superman.
So, here are three ways Quicksilver could logically (and most likely will) return in Avengers: Infinity War.
1. The Tablet Of Life And Time
As a part of Odin's vault, the Tablet Of Life And Time is a very powerful object that contains a biochemical formula within the stone for a serum against death itself. The stone could bring the dead back to life (even without the deceased in close proximity), heal the living, and give the user the full potential of their power. That was in the comics; as of now we have yet to seen its effects in the #MCU, but we can safely assume they are the same.
Is it possible that when Thor left to Asgard in Age Of Ultron, he went to his father's vault to revive Quicksilver? Maybe I'm going out on a limb here, but after research on the artifact, I found that when in use, it drains energy from other life forms in order to heal the user. The energy being drawn can come from cosmic beings and even cause Ragnarok. Also, if the stone really gives users full potential of their abilities, we could see a much "quicker" Quicksilver!
2. Kree DNA/GH.325
The GH.325 is DNA gathered from a Kree corpse secretly acquired by Nick Fury for experimentation. When found the Kree's DNA could bring the dead back to life or heal drastic injuries, director Nick Fury made sure it was kept hidden. Only a few scientists knew, and the samples were only supposed to used for mortally wounded or dead Avengers. However, when Phil Coulson was killed by Loki in The Avengers, Nick Fury used it to revive him.
When Phil's team discovered GH.325, they only managed to gather one vial before the entire secret base went into self-destruct mode. Luckily, Jemma Simmons and Leo Fitz were able to recreate the formula, but never spoke of it again. While the current situation with the Inhumans may be wild, it wouldn't surprise me if S.H.I.E.L.D. took drastic measures to make sure the fallen Avenger would live to run another a day.
3. Helen Cho's Cradle
U-Gin genetics expert Helen Cho constructed the Regeneration Cradle, a device capable of manufacturing and printing real human tissue. It was originally meant to heal open wounds and rebuild the damaged layers of skin. We saw this was a success after it was used on Hawkeye, but Iron Man later found out the machine was fully capable of not only regenerating the worst of wounds, but of printing an entire humanoid body that could live on its own. Some have even said this is the most important item in the entire MCU, and could have a bigger purpose in #InfinityWar. If Quicksilver were brought back, this would be the most probable scenario, as the tech would be easy for the Avengers to access and could quickly bring back their fallen Avenger.
Some people like to believe Quicksilver will be brought back after the Time Gem (along with the other five Infinity Stones) is in safe hands after Infinity War is over; however, this seems like a cheat. There would be nothing to stop Steve Rogers from wanting to bring back Peggy, or Peter Parker and Uncle Ben, and that's something #MarvelStudios definitely won't do. Avengers: Infinity War hits theaters May 4, 2018!