Adjust Masteries to deal with Tank-Assassins

This whole season has been about champs abusing whichever keystone mastery is strongest, and this has been especially clear with the rise of tank-assassins; champs like Ekko, Fizz, Akali, Master Yi, and Yasou. They build full tank, but because of the masteries that they are running, they still deal absurd damage. Most recently Gnar has been rushing Frozen Mallet into a full tank build, but since the build runs Fervor of Battle, he still deals a ton of damage, even though he builds almost no AD.

Same goes to tank Akali running thunderlords, or Fizz running fervor, Yasou running almost any keystone, etc. The keystone masteries, at least as far as the damage ones, are giving way too much free damage.

But here's how you can fix it. The only ones that really need to be looked at are: Fervor of Battle, Stormraider's Surge and Grasp of the Undying. Warlords Bloodlust isn't that big of a problem, and Deathfire Touch should really be looked to as a model for how masteries should be set up, since it has almost no base damage and requires you to build AP or AD in order to increase its damage. Stormraiders Surge, Windspeakers Blessing, Strength of the Ages and Bond of Stone offer no damage but are decent in terms of the small amount of utility/stats that they provide.

So, what to do about these masteries?? Increase their ratios, reduce their base damage, and possibly change the way in which some work.

Fervor of Battle for instance, which can grant up to 112 bonus on hit damage (7.2-111.9 based on level, with max stacks) can dramatically increase a champions DPS. It is a favorite of tank AD assassin and on-hit builds since you get a boatload of free stats to make your damage relevant while you build tank. Personally I would like to see Fervor changed to a stacking mechanic that increases your Bonus AD when attacking champions. That way, the ADCs who run it still get something out of it, but the champs building full tank lose out on it.

Thunderlords should have its base damage reduced, and its ratios increased. Simple as that.

And Grasp should lose its damage component that is making Juggernauts and Bruisers stronger by adding more damage into their kit, and instead it should heal the user for more. So instead of "stealing" 2.5% of your health on proc, dealing that as bonus magic damage and healing the damage dealt, you would instead heal for a larger % (3.5, maybe 4??) but deal no bonus damage. That mastery is about a tank/bruiser clinging to life (hence "undying") rather than dealing extra damage.

With lower base damages and higher scaling across the board, it would certainly curb to appearance of Assassins masquerading as tanks