We have seen some pretty cool superheroes with powers but lets take a look at the one's without superpowers you think they're powerless NO they have something better "SKILLS" some trained by assassins some train on their own here are my TOP 5 list of assassin characters.
Number 5 : Mockingbird (Agents Of Shield)
Mockingbird is one of the best assassin in the Marvel Universe with her twirling sticks and her mad rad skills and lets not forget her ways of interrogation and that's what makes her one of the best assassins in the Marvel Universe.
Number 4 : Desmond Miles(Assassin's Creed)
Desmond Miles the son of William Miles is a very trained assassin with his skills his stamina his agility he is the only boy assassin on this list the best handsome,trained and respect others that's what makes him the best boy assassin.
Number 3 : Gamora (Guardians Of The Galaxy)
Gamora is a good assassin trained by the Kree empire and the daughter of Thanos himself but greatly she turned against Thanos.Gamora also has a title The Deadliest Woman in The Galaxy.
Number 2 : Black Canary(Arrow)
Now try and compare the Black Canary and Mockingbird there is no way Mockingbird can defeat her she was trained by the League Of Assassins to become the Black Canary she was taken in to be Ra's Al-Ghul step daughter and trained to become the best.
Number 1 : Black Widow(Avengers Age Of Ultron)
Black Widow surely wins this round even if she were to go against Black Canary she would definitely win no one would be able to fight the Black Widow and win I mean come on she is tactical,stealthy,skilled in hand to hand combats and she gets a head start with her stinger so yeah Black Widow wins.