[*Note: Watch out for spoilers for several prominent Deathstroke storylines below!]
There have been a lot of great stories featuring Slade Wilson alias Deathstroke. Examples range from the cartoon Teen Titans (2003-2006) to those two issues where Oliver Queen/Green Arrow was mistaken for Slade (Green Arrow #’s 84 & 85 circa 1994). However, I am of the opinion he should not have a series based around his character. Yes, many of his fans reading this are probably thinking of various negative things to say or things to do to me in response to this claim. Therefore I will explain my reasoning.
First off, while many readers love the “Judas Contract” storyline, it is also a storyline where Slade sleeps with the underage Tara Markov (the original Terra). Yes, one could argue consent was given based on her own personality, but the retcon presented in the one-shot DCU: Last Will And Testament (2008) suggests otherwise. In said one-shot, Slade supposedly had drugged Terra with a mind-altering substance. Thus, Slade was essentially responsible for date rape at least once.
If the original version of the incident had not been compounded by that one retcon then my first bit of reasoning would not be as hard-hitting. Unfortunately, that is not his only crime. He has also used the previously mentioned drug on his own daughter (Rose Wilson), and is the reason his son (Joseph Wilson/Jericho) was almost fatally injured as a kid. Personally, even if I can look past the killing, and other villainous acts, I cannot understand why he essentially has gotten the “Luke Spencer treatment.”
For those wondering what I am talking about, Luke Spencer was a soap opera character created specifically to commit sexual assault and then die. However, for various reasons, including audience reception and Anthony Geary playing Luke as feeling guilty, he was given a redemptive story arc on General Hospital and became one of the most well-known anti-hero characters in the history of that genre. That said, Deathstroke has never been written as feeling genuinely guilty for any of his actions. Yes, he has helped the heroes at times, such as in Dark Nights: Metal, but he always has something to gain or lose from these situations.
If he had a genuine redemption arc of the kind that seems to be occurring with (Killer) Frost in the current series Justice League Of America, then I could see how he might have a title. While it could be argued that his status post Titans: The Lazarus Contract is a redemption arc, it is one created and based off selfish desires, and in my opinion that makes it far from genuine. As it is, I believe he has been given his past, and current, series due to the toxic masculinity leftover from the hyper-violence fueled entertainment of the 1980s and 1990s.
That all said, whether Deathstroke continues to have a future as a titular lead will always be determined by creative/corporate interests and reader support.