Quicksilver

Qiucksilver, an alter ego of Pietra Maximoff is a fictional superhero created by Marvel Comics and has appeared in the Avengers' franchise as well as the X-Men film series and was portrayed by two different actors in the two different franchises. Quicksilver possesses superhuman speed exceding the speed of sound. Quicksilver initially fought against the Avengers alongside Scarlet Witch but later joined them as they learned the cause.Quicksilver is trained by Captain America in a hand-to-hand combat.