Yasuo, Riven or Kalista

I'm having mixed thoughts on what my next Champion should be. I like Kalista's Passive, but I'm not to keen on the rest of her abilities as they seem like they do no damage. I like Yasuo's ult as it can get more than 1 person, and I like Riven's Q because of the escape potential it has. I just don't know . I'm not afraid to learn a new champion as-well, Soo yeah! Thanks for helping me out