- Quicksilver Sash only builds into an AD item (Merc), leaving it as a sub-optimal investment for mages
- New item Edge of Night blocks the next spell for 10 seconds, obviously aimed at Assassins preparing for a kill, to avoid getting CC'd as soon as they break stealth (another thingy about [counterplay](http://boards.euw.leagueoflegends.com/en/c/champions-gameplay-en/h6dZAUjF-riot-make-up-your-mind-about-counterplay) )) , also only useful for AD champions.
- Yes, mages have Zhonya's, but that is almost the opposite: it locks you into place by its own effect, basically what you want to avoid most of the time. Also, AD champions have Maw of Malmortius as a substitute, which is another item keeping AD champions mobile while preventing death.
Please introduce an AP item based on QSS...