There was a lot to him before. But the Gul Dukat we all know and love died along with Ziyal in Sacrifice of Angels. After that, he had no reason to pretend anymore, and the demon was allowed full play. Had Ziyal lived, maybe Behr could've been wrong, maybe she could have helped him graft that mask of gentility and kindness onto his heart, make it no longer a mask. But Damar killed that just as surely as he killed Ziyal, and all that was left was a hate-filled, vengeful husk of a man.
I believe they should have killed him after SoA
I hated, hated, HATED, with pure malice, Sisko's line in Waltz: he is pure evil.
if nothing else, that was revisionist writing on the part of TPTB.
Two possibilities here. One, this is Sisko's belief, and we're not beholden to agree. Remember, this is the man who used biogenic weapons against Maquis settlements without Starfleet orders, and the man who was an accomplice (at best) to a double-murder in order to get the Romulans on the Federation's side of the war. Sisko has a demonstrable problem in demonizing his enemy, as we can see in Eddington, Picard/Locutus, and Solok, and now in Dukat.
The other possibility is that Sisko's right, in stating that he is - present tense - evil. Not that he was evil, he is evil. It's not revisionist writing if the implication is that losing Ziyal (and his empire) drove him over the edge and ripped away forever the mask he'd been wearing. It's unfortunate in that it's painting a psychotic, insane person as evil, but that's one commonly-accepted belief, and the nature of evil is a debate for another thread.
I would agree about killing him after SoA, except that I thought Covenant was a very good episode, and the intentionally-mythic Emissary/Anti-Emissary plot started in TotP was a good idea, if somewhat flawed in execution.![]()
It's presented in a way so as the audience is supposed to be beholden to the Sisko's opinion about Dukat being pure evil and accept the nonsense BS that they tried to retcon into Dukat's character (ie: he really wanted to massacre all the Bajorans etc.). Definitely some major revisionist history going on there that contradicts earlier episodes which show Dukat helping to improve the quality of life of Bajorans and also going out of his way to not massacre them (ie: Civil Defense).
They didn't present Sisko's anti-Dukat spiel on-screen in a way that says Dukat used to be good and then became evil. Rather they added that nonsense BS retcon to try to force Behr's opinion that he was always evil down the audience's throat.
As for Dukat going insane because Ziyal died, that too is very ridiculous. He was fine before he met Ziyal, and he would likewise continue to be fine after she died. And if he was going to blame anyone for killing Ziyal, it should have been Damar who murdered her rather than Sisko who had absolutely nothing whatsoever to do with it.
There is no reason why Dukat had to be an anti-Sisko. The only way that could have been done well is if they made the Pah-Wraiths into sympathetic entities with a perfectly valid point of view that are just as good, if not better, than the wormhole aliens, which indeed could have made for one of the best out of any Trek storylines rather than one of the very worst, which is what they actually did with that was, by going for good vs. evil caricature instead of the complexity like Dukat has for 6 years prior to Waltz.