Idea to help balance masteries.

So I was singing to myself in the sower when I realized something. Masteries are basically stat-sticks/actives/passive you get for free with no effort/drawback at all. I was thinking what if you made it so that there was some short of repercussion to taking a keystone such as a tier before keystones that take no points but all had quirks that stopped the people from abusing mastery trees and still get to keep their innate advantages like keystones that decreased damage before taking a keystone from that.... tank tree (don't remember the name.) Or you could just tie specific quirks to each keystone like you deal less damage when CoC is active or Warlords bloodlust decreases attack speed when you are at a specific percent health and attacking enemy champions so you don't drain tank but can still leave battle and sustain from other sources.

Also this is me diverting from my original discussion but I don't think that CoC would be as much balance-able as an armor/resist buff more so than it would as a shield. What I mean is when you CC someone you get an increase in armor/magic resist based on bonus defenses and the number of enemies present. This would also go with the debuffing idea so people wouldn't get tanky with and be able to kill everything in sight. Also the damage reduction could also be based on the number of enemies in the vicinity. That way it wouldn't screw people over too much in lane.

I mean you have to reach to reach level 30 to get full mastery set but when you do most people just end up going to mobaflair or just taking the most broken keystone (CoC I choose you). This could make masteries a more dynamic choice than just copying what everyone else does