User blog comment:AXE MURDERER/Yasuo is disgusting/@comment-24346528-20131228135834/@comment-24191093-20140106163644

You can't cleanse knockup, and tenacity doesn't reduce it. Here's the description from Zephyr:  Unique –  Tenacity : The duration of stuns, slows, taunts, fears, silences, blinds and immobilizes are reduced by 35%. Doesn't affect knockup. I don't think you can cleanse Yasuo's CC either.