@riot: when is strength of the ages getting buffed?
the way i see it, there are 2 problems with the keystone
a) its unreliable compared to the other 2. its effectiveness is tied to getting those cannon minions to build up stacks. means youre forced to stay in lane because roaming would make you lose out on those stacks.
meanwhile grasp and bond of stone always have a reliable effect.
plus other eventualities like getting zoned from those minions that might prevent from getting cannons. once fully stacked, those 20 hp heals from cannons are entirely irrelevant, as the game has long moved past the lane stage.
b) you get less out of it than the other keystones. in extended fights/trades like typical between tanky champs, grasp of the undying and bond of stones damage reduction grant as much additional health while having a secondary component added to them. either the damage or the damage reduction on a secondary target.
with the nerf to veteran scars health bonus, its time to buff the keystone by moving the lost health down to strength of the ages.
i propose instead of using the unreliable stacking mechanic, to just have the keystone grant 10% max health as a bonus.
if we say a 3.5k to 4k health fighter/tank previously got 140 to 160 health out of veteran scars, giving 10% max health on strength of the ages would almost make up the 100 to 120 health loss after the nerf. (the current 300 hp + 100 hp on a 4k health champion).
also, bonus question. with the addition of the assassin mastery in the cunning tree. do you have other t1 and t2 masteries for the other 2 mastery trees in store?
the stacking mechanics as stands presents a good way to increase your actual physical hp's with little or no additional effort on your part. 
and 
both work well with this mastery as either you or the adc (depending on start item) should already be focusing on last hitting the cannon minions above the other farm minions as they are worth more. Sure you may loose a few in mid trades, however if you manage to win the trade the payoff is worth the loss (assuming you don't have to back off and end up as food for the enemy jng shortly after).
needs at least 3k hp to proc passive, and strength of the ages is a good way to boost your current hps to make that goal achievable early game. I have had a working 
cough). In bot lane maybe you are doing extremely well tho have an unskilled adc (and there are plenty out there who cant adc, myself included) it's your job to make up for their slack even if your jng has to help shoulder the burden until you and adc are fed enough that crappy playstyle can no longer be used as an excuse (save for the intentional feed). That actually brings me to my next point, why stacking over a flat boost?
, and even 
completely and disproportionately out into the nether realm of being completely op? Mundo and garen both have annoying, and somewhat unbalanced healing as is. adding a flat 10% to their hp and by abilities means regen would only make them harder to kill at all levels, granted that is the way their kit is designed to be, however adding a 
and/or 
and 
only helping to make these match ups all the more feared. Vlads passive (40 hp = 1 ap and 1 ap = 1.4 hp non-self-stacking) perhaps can display the best example of why a flat percent boost is just too unbalanced. With vlad it isn't uncommon to see 4037.8 hp (1987 base hp at 18 without runes, items, masteries, abilities, or abilities. liandrys 300, ryli's 400, warmogs 850, visage 500 at full build and level. Even at a 10% boost thats 403.78 bonus hp for a total of 4441.58 hp (discounting his passives transformation of any ap to hp) giving a 111.0395 bonus ap with his passive. doesnt seem like much right? but add that to fairly common ap items on him (liandrys 80, ryli's 100, rabadons 120, will of the ancients 80) for 491.0395 before rabadons passive 20% increase which gives 98.2079 bonus with the theoretical build to total 589.2474 (478.2079 of wich gets put tward more hp (yes i subtracted what he got from passive from his final ap before calculating his ap to hp gain) for an additional 478.2079 hp) In total this resaults in a vlad with 4919.7879 hp and 589.2474 ap. Not something I would like to meet in game. Finally thought I forgot about sona? well her impact would gain a minimal boost as she tends to stack ap over hp, however simply put more max hp = more heals she can do before having to base or worry about being killed by a minion (or champ for that matter) for trying to line up her starfall.
or 
which can absolutely devastate enemy teams who rely on items like 
or stuns. every support should be equally aware of their marksmans strengths, weaknesses, kits and that of the oppositions and help their team overcome the incoming threats, not just focus on keeping them supplied with one helpful thing.
