Had a Renekton cry about Garen claiming he could not beat him because the new juggernaut is OP...my gator teammate built thornmail as his first item :/
I mean...
The dude has a winrate of 55.3%, and you don't really get to play the game if knows what he's doing. Riven mains or not, they're right in that he needs adjustment.
I regularly used Garen in ranked before his latest rework and I can say after playing a bunch of both the new Garen and the new Darius that I feel stronger at all stages of the game with new Darius. You have 2 90% slows in lane folks. Setting up Decimate in lane is not as hard as people claim, and landing even 1 or 2 can cause such heavy swings thanks to its damage and healing that you can take over a lane.
there is nothing more devastating to the enemy laner then an extended trade where you both end up 40-50% and landing a second decimate.
and mid/late game you are hands down more terrifying and tanky thanks to decimates borderline broken self healing once your items start building up. 
A Riven in my game fed a Darius and said hes op. kek.
Wat?
What is this horror?