**Warning: This article includes spoilers for the majority of the Marvel Cinematic Universe (MCU) films.
As you know after watching the Avengers: Infinity War, many characters died after Thanos snapped his fingers, including Black Panther, Spider-Man, and Star-Lord. Just so you know, according to writers and other sources, these characters are not coming back to life. In fact, after doing some research on remaining Marvel characters and going through all sorts of theories, I am very assured that the end of Avengers 4 would be more shocking.
Let's consider two cases which would happen in the Avengers 4: First, either Thanos will kill himself or become a nice guy. Second, more than one superhero will kill him to protect the Universe and distribute powers in many hands. Based on some in-depth research on remaining Marvel characters, I think Captain Marvel (Carol Danvers) is one of the most likely candidates who will be able to kill Thanos, if Marvel Studio does not introduce any new superhero.
Often in my dreams, I have found myself as a superhero, saving everyone's life or saving planet Earth or even an entire galaxy. In my fiction(dream) world, I am a guardian of the galaxy. To fulfill my desires being a superhero for real, I wish I could switch with one of the superheroes for a week. If I had given a chance to do so, I would love to switch to Captain Marvel because if she had to kill Thanos, I would take that opportunity with pleasure.
Captain Marvel is one of the abundant batters in the Marvel Universe, alongside Hulk and Thor, but little stronger. Exceeding her super strength, flight, and energy explosions, she can likewise absorb energy as distinct as antimatter as Blue Marvel, but she has a lot more to show. The more power Thanos would use against Captain Marvel, the more powerful she would become. It will be too much fun to watch.
As Being Binary, Captain Marvel has every one of the forces of a White Hole, energy, comprehensive measures of heat, gravity, light, and also a level of vast mindfulness that lets her discover her way through space and sense uncertainty. Captain Marvel would most likely use M'Kraan Crystal to defeat Thanos alongside help from some of her alien friends in the other part of the Universe which may include Arsenal (a robot that has been designed to store the enormous amount of energy).
Adam Warlock, an artificial human, Captain America, Iron Man, Thor, and Hulk might appear in the team of Captain Marvel, but they think they are already retired so not counting on them. If they actually wanted to do something, they should have done it in the infinity war. But it's done! Better luck next time folks, you have disappointed me. Since Captain Marvel is one of the guardians of the galaxy, it would be my pleasure to switch with her just for a week, so I can absorb energy and have the power of white hole. All right, it is now time to wake up! Enough dreaming :) See you next week!