What makes Darius as strong as he is? His passive.

I see all these changes to the rest of his kit, but his Passive is left as it. Am I the only one that believes this as well? I mean for all the talk about 'Invisible Power' Darius has been granted one of the biggest 'invisible powers' there is.

Why do I believe the passive is what making Darius so oppressive? Because it punishes players for trying to trade with him.

That's right. Laning phase? You're not allowed to trade with Darius. That thing you do with practically any other lane opponent to try and assert yourself in lane. Why is this the case? Because Darius's passive with ensure that he wins practically ANY trade in lane. Because if you try to trade with Darius, then you'll find yourself being slowed down to a absolute crawl. You try to get away from him? He pulls you back and more than likely will proc his passive, meaning you HAVE to run away from him all the more. This threat is why Darius is so strong. Because he strongly dissuades you from engaging in trades with him.

I don't see why Riot downplays abilities/items/passives that give invisible power, but then allow Darius to have a passive that's among the best invisible powers in the game. So strong that it stops players from wanting to engage trades with him and demands the enemy jungler as well as other allies if need be, to camp him until he's crippled.

The only other champion that comes close to this oppressiveness would be Morde. Morde forces tries to intimidate you into not trading with him because his support with CC you and you'll end up being whacked 3 times by his Q, which will be insane damage regardless of it being early, mid, or late game.