Trynd isn't actually that bad, I easily shut him down every time I go against him, from people that range between Gold-Plat that have a decent idea on how to use him.
Yasuo on the other hand.. Well he makes Trynd look like a joke. I main Yasuo, but I know he is broken right now so I already know he'll get nerfed I don't mind, I never really play Trynd though, all I know is, you just need to know how to shut him down. Takes team work, not solo work. Since.. it's a team game.
I really don't see the issue with people and Trynd, I literally haven't lost 3 out of 3 games games while he was in the game on the enemy team. The only reason most champions feel overpowered right now is mainly because...
AP items = Nerfed.
AD items= Buffed.
= AD champions being a bit too overpowered for the mages to handle.
Mages will be buffed I'm positive, or AD will be nerfed (I highly doubt) .
If I may ask, how is Trynd broken? I laned against this guy several times and had proper ganks which has shut him down to oblivion every single time. All you need to do is Kite him down/Ignite him (When his hp is at the limit obviously). Yes he gets hp per crit he does, but I would kinda blame your team for standing in 1 spot letting him get slammed by Trynd 24/7 so he's able to gain HP, might as well say your team is auto healing him/assisting enemy team.
On a side note, I don't really care if he gets nerfed, but I find it dumb to nerf a already simple champion to take down if you know the basics of the game. I've only played Trynd 2 times my whole league life, so like I said, I could care less if he is nerfed, I don't main him, but I would feel bad for the people that do.