You cant say any hero is the best 1vs1 hero. Everything depends on how u farm and how clever are you to use the hero u picked.

Skill is the most crucial thing you must have before ur hero.

I usually own people when I play allrandom because most of the people tend to just train a specific hero, so when they got the hero they never use before then they sucked.

But for me I train my skills. So I can use any hero in the game because I know when to use my skill and what am I supposed to do when i'm engaging with enemies.