What does it take to be pro?

It takes raw skill, a functioning brain and good behaviour.

professional means that youre getting payed for what youre doing.

you can be complete shit at your profession, but still be a pro.

A satanic ritual so satan puts the feeders on their team for a damn change

to climb in ranked? lots of time, thats about it. providing you stay at, at least 51% WR it may take a while but you will climb up if you have enough time to invest.

Being a pro takes skill, game knowledge, mechanical knowledge, great reaction times, etc.

League of legends and other Esports where pit against Jet fighter pilots, the gamers reactions times came in at 0.25s slower than that of a fighter pilot, to give some perspective.

Dedication, practice, perseverance, proactive/reactive play and a grasp of theory.

be good at the game

1. Taking away your life and dedicating it to league.
2. Never have any friends
3. Be anti-social
4. Be a virgin
5. Miss all your skill shots
6. Be pasty white
7. Have a bowl cut
8. Find a team on League
9. Git Gud
10. Compete in Challenger Groups

Short answer

making enough money out of playing the game

then it can be your profession

thus making you a professional