User blog comment:Willbachbakal/(Item Concept) Crowd Control/@comment-5035765-20150101042731

well... the thing with Quicksilver is that its stats honestly aren't too terribly good, and you're sacrificing an item slot so that you can have that safety net. Plus,  getting rid of all CC Removal suddenly makes the skillcap for the champs countered by it go way down, and the skillcap for everyone else go way up, since the person getting CC'd has to predict when the CC is coming. And since these champs would be so much stronger, they'd be more common, so being able to win may come down to "are you any good at timing when people will use this skill", which is kind of annoying

as for Phase, it'd be a near impossible thing to balance, because the CC immunity is kinda short, but any kind of long term invincibility is rather unwanted (imagine if Tryn had CC immunity during his raging... or hell, Poppy using her ult on a low damage low utility enemy and charging the rest of the team). So if Phase ever got into the game, the invincibility and CC immunity would NEED to have different durations.