"Faux-Hawk," the penultimate episode of Titans season 2, has rendered Deathstroke's quest for revenge completely nonsensical. While the story behind how Slade Wilson came into conflict with the titular team was already convoluted, "Faux-Hawk" found a way to complicate matters even more, as it disproved a number of popular fan theories.
The central plot of Titans season 2 focused upon Slade Wilson's grudge against the Titans and his plan to destroy the team. It was revealed over the course of the season that the reason Deathstroke hated the Titans was because they were responsible for the death of his son, Jericho. In truth, Deathstroke killed his own son after Jericho threw himself onto his sword in an attempt to save the life of Dick Grayson. However, this did not stop Slade from blaming them for the circumstances leading to Jericho's death.
"Faux-Hawk" opened with a flashback confirming what Dick Grayson had guessed in the final moments of the previous episode: that Jericho, who had the power to telepathically possess other people, was still alive in Slade Wilson's body. This led into a scene set in the present day, where it was revealed that Jericho was now a prisoner in Deathstroke's head, struggling for control. Ironically Slade had come to value what had been brought about by his accidental filicide, telling Jericho that it had "brought us together," though Jericho described the experience as "five years stuck inside this Hell."
There are several problems with this scenario, with the chief one being that there's little reason for Deathstroke to seek revenge for the death of his son when Jericho is still alive in all the ways that matter to Slade, and Jericho has outright said he doesn't want his father seeking revenge on the Titans. Another problem is the idea that Deathstroke has the strength of will to resist Jericho's control, when Jericho's powers up until this point didn't suggest that a psychic battle of wills was a possibility when he possessed someone. Indeed, Jericho was able to possess Hank Hall, who is probably the most stubborn and willful character on the show, with no difficulty.
The biggest problem with this revelation, however, is that it makes less sense than the than theory that Jericho had possessed Deathstroke and turned upon the Titans to keep other kids like him from being killed playing superhero. Not only does this idea have the benefit of having been taken directly from the Teen Titans comics. but it would explain why Deathstroke seemed so hung up on the point of the Titans coming together and why he bothered with all the cat-and-mouse games using Rose to break the team up from the inside. Taken as presented, there's no logical reason why Deathstroke couldn't have just saved himself a lot of trouble and planted a bomb in the basement of Titans Tower if all he wanted to do was kill all the Titans.