First I'd like to start off with a quote from Riot:
“Individual items grant fewer stats but now feature a one- and two-piece bonus which preserves the power spikes of assassins’ first big purchases,” Riot said. “Since this set bonus stops at two, assassins should generally branch into raw-AD items like Guardian Angel or Black Cleaver after their two-item spike. Full Lethality sould still feel like a strong option against exceptionally squishy comps, though.”
The generally part made me kind of laugh because when I realized that this might be the case for MOST assassins. But the one assassin I was thinking about has not only his ultimate scale with lethality, but his E stun. The fact that Pyke will be making more gold with the new support items and gain AD from the new support items while not needing to upgrade his support item with that gold mean he can buy more stuff. And if he can buy more stuff, that means he can literally build lethality and keep ulting his enemies to rake in all the coins he needs to go full lethality Pyke. I think I did the math right, and if Pyke gets all 5 of the new lethality items (which would be harder for support Pyke but maybe doable for solo lane Pyke), his ult threshold would be at about 900+ hp while he could deal about 300+ damage per auto flatly to any enemy with less than 84 armor. He would gain lifesteal, 30% cdr, and an attack speed steroid that would activate when he 1v1's enemies. Once again, feel free to correct me but the support changes and assassin item changes seem to benefit both roles to be sure, but it culminates in a direct buff to Pyke as he can continue to build lethality.
As for Yasuo, it seems that every crit item in the game can now be made with Cloak of Agility. This is further compounded upon by the fact that they are buffing cloak so that it gives +25% crit. For botlane, this means that when Yasuo and the enemy adc make 1600g, they can both buy two cloaks. Yasuo, though his crits deal less damage, now has 100% crit chance while his enemy has only 50%. The only other champion that would be able to do this is Tryndamere for top lane and maybe Senna. But the reason I picked Yasuo was that with the new drake and Conqueror changes, his ability to ignore armor seems to be better than Senna or Tryndamere getting 100% crit earlier.
These are just some opinions. Any thoughts?