What are some of the darkest/most mature episodes of kid friendly cartoons?

My take would be the Trigon story arc from season 4 of Teen Titans
>Deathstroke comes back from the dead as a demonic messenger
>confronts Raven and strips her in a way that resembles a rape scene, and informs her about her apocalyptic destiny
>eventually gives into her father's command and summons him to enslave the earth, after trying to give her friends the best last day alive she can
>earth turned into an apocalyptic hellscape, like something out of a death metal album cover
>hopeless vibe all around, Robin has to travel with Deathstroke to the bowels of fucking hell to find Raven reborn
>meanwhile other titans have to fight their evil clones who prey on their deepest fears and insecurities
>Slade splits off from Robin to fight and kill an executioner-type demon to get his flesh back, helps the Titans take on Trigon
>only a thick layer of plot armor in the last five minutes of the last episode in the arc ends up saving the day
>ends with some message about hopefullness and always looking positively into the future even though the entire arc was a hopeless and brutal journey when everyone thought they were screwed

We were brave as fuck watching these shows as kids.