Yasuo should get nerfed on the key stone mastery that can heal for 15% of your crit
I tried one or two games of yasuo one PBE, and found our as soon as I get some crit on him, I dont even need life steal to sustain. His crit chance are so high and the heal only has a 3 second cooldown where you can constantly heal for 20+ healh. Some change should be made, because this is an extremely high snowball potential.
Once he get a kill or two in lane( usual yasuo stuff), he can just go for full damage+crit while having extremely high lane sustain. This is just not fair for then opponent player, where there is just not outplay for this.
main here, gotta say that you have a fair point (though I've been skeptical of these masteries since I found out about them). Though, I don't think you should be worried about Yasuo with this right now.