Pretty much everything involving the Kraken, starting with Ed's absolutely horrifying expression right before he throws Lucius off the ship to drown.
2x1 - Impossible Birds
Wondering how Ed's career as the Kraken is going? Well, so far he's cut off two more of Izzy's toes as punishment (and his conversation with Izzy implies that Izzy has just let him do it), is constantly high, shows no concern for his crew's lives, randomly threatens to kill his crew and himself for daring to be unhappy about this state of affairs and shoots Izzy in the leg for saying that it's because of his feelings for Stede. He's gone on dozens of raids to break a record, making the crew dump the treasure they've stolen into the ocean to lighten the ship before their next one. The end of the episode is him announcing to Frenchie that he plans to never set foot on land again.
Meanwhile, Izzy has apparently been weathering the brunt of Ed's insanity, which the entire crew recognizes. Merely pointing out that he has an unhealthy relationship with Blackbeard is enough for Izzy to break down in tears in front of the crew.
Half of the episode is the crew's attempts at hiding Izzy, who is still alive but severely injured, from Blackbeard. Frenchie has several scenes where he unconvincingly lies that Izzy is already dead, until Blackbeard reveals he knows Izzy must be alive because he recognizes the smell of Izzy's rotting flesh.
It's played for laughs, but Lucius has clearly been through severe trauma ever since Ed pushed him overboard: after an undeterminated amount of time in the ocean, he was picked up onto a ship where he was forced to eat a dog, catch rats with his teeth, and other humiliating forms of torture for the crew's amusement.
After a brief Hope Spot where he seems to be calming down, Ed is terrifyingly suicidal by the end of this episode, steering the ship into a raging storm, disabling the wheel, and telling Jim and Archie to fight to the death of he'll blow up the mast. Which he says he was going to do anyway regardless of whether Jim and Archie fought or not.
The cursed ship, which has, among other things, dead bodies with their eyes gouged out, a pentacle written in blood on the deck, and a dying priest who tries to warn them of the curse.
