Extremis virus is an ultimate key to having powers like Iron Man. When injected in host organisms it transforms them into a giant house of superpowers like super strength, super agility, super speed, super healing factor and makes them super in anything they do. However, it causes unbearable pain and trouble until it completely settles inside the body. Tony Stark knows the taste of the serum, while there are several others who used it to enhance their powers. Check out the characters who used the serum besides Iron Man.
One of the rising and brainy scientists in 1999, Alrich Killian was running an organization Advanced Idea Mechanics and always looked out for sponsors for it. During new eve party in Bern, he counters Tony Stark and asks him for some business proposition. Killian waited for him at the terrace, but Stark didn’t come. After few hours, he decided to commit suicide. But then he didn’t. One Killian’s recruits Dr. Maya Hansen had one night stand with Stark, who brought him Extremis serum from Stark which enhanced him.
2. Eric Savin
Eric Savin worked under Aldrich Killian. During a visit at Stark Industries, Savin came across Happy Hogan and that’s when takes his guest pass. As he left before Killian from the visit, Hogan followed him where he passed ampules to an Extremis subject. Savin was already an Extremis-enhanced man who was stopped by Hogan. Later, due tot the altercation of the virus it exploded the other man.