He's not buffed or nerfed that often. He's always viable in LCS, but in soloqueue I would highly not recommend picking twisted fate unless you truly are dedicated to mastering him. He has a very weak early game and laning phase, and until late game he has only one ability-his ult. It gives him insane map presence and a really good twisted fate will be able to use this every time it's up to secure kills and feed his team, until late game where he can pop people with W Q.
At level 17, I would not worry about meta however. Play what you enjoy playing, never play a champ because they're "OP". That extends to everyone too, not just people new to the game.