8. Black Panther
T'Challa made his first appearance in the Marvel Cinematic Universe in Captain America: Civil War and during that time he managed to take on two super soldiers at the same time. If that's not making an entrance, I don't know what is.
The Black Panther's strength originates from a purple heart-shaped herb that grows in Wakanda. Once consumed, it gives the Panther incredible strength, speed, cat-like agility, and durability. And speaking of durability, the Black Panther suit is made out of Vibranium, a.k.a. the same metal that Captain America's shield was made out of.
If you went up against T'Challa, you were in for a fight. The Black Panther was relentless, taking on all comers and putting them through it. He could outfight you, outwrestle you, and outrun you, making escape all but impossible. And honestly, we couldn't think of a better protector for the kingdom of Wakanda, because with T'Challa watching over them, they were always in safe hands.
A new Black Panther has risen in the form of T'Challa's sister Shuri to carry on his legacy. She is also all of the things that her brother was, but it goes without saying that we miss the incomparable Chadwick Boseman and all that he brought to the world.