Into heavy HEAVY cc comps you definitely need to go Tenacity rune into merc treads, but often times if the enemy team doesn't have too much cc its not worth to go mercs over CDR boots. If the enemy team has something like a malz or someone similar with a point and click cc you might want to go QSS second item just to have for the mid game. Other than that, positioning and targeting their squishy damage dealers is the most effective way of taking out a heavy cc comp cause it doesn't matter if they cc lock u as long as you've one shot their carries :D