||11-14-2012 12:06 PM
Tenacity doesn't effect such skills, as the animation times for knock-ups are pretty inflexible, so you get incapacitated for the full duration (Pulverize, Unstoppable Force, Blitz Punch, Wukong Ulti, Nautilus Ulti). They don't effect displacement either (Rocket Grab, Headbutt, Dissonance, Diana Displace, Tristana Knocback, Condemn, Poppy Charge, Singed Fling, Volibear Fling, etc.).
Which makes CC Bots like Blitzcrank and Alistar rather hard to deal with, as they both have 2 forms of non-mitigatable CC. (Quicksilver Sash and Cleanse also won't remove such CC effects once the CC is applied). Effects that grant immunity to CC prior to it's application, such as Black Shield and Ragnarok, will prevent such CC effects from occurring though.
Also, considering it reduces the duration of CC rather than reduces the strength of the CC, any ward-like effects that constantly apply CC while you're on it are largely unaffected by tenacity as well (Mega Adhesive, the Slow portion of Viktor's Slow, Anivia's Ultimate), though if you have a gap-closer you can generally avoid the slow by jumping off of it.
Anyways, here's the LoL Wiki article on Tenacity