Could we give Courage of the Colossus the same treatment as Steraks?
It was (And some cases still is) an intensely satisfying keystone to use for tanks and juggernauts, but unfortunately due to abuse by lighter bruisers as well as being too strong early it was nerfed pretty hard out of necessity.
But if they made the mastery scale with Bonus health (Such as 8%), it would prevent less durability focused champs from abusing it and be able to serve as a general balancing lever for tanks without having collateral impact on other low cool down CC Champions.
Just a small change I think could be pretty nifty, plus we're revamping tank gameplay anyway so a change to the mastery wouldn't be too chaotic.