Though Arrow’s Deathstroke hasn’t made any appearances post-Crisis on Infinite Earths, he was definitely affected when the multiverse was reborn. Numerous Arrowverse characters had their lives changed when Oliver Queen (Stephen Amell) used his Spectre powers to create Earth-Prime in Crisis on Infinite Earths, and Manu Bennett’s Slade Wilson was no exception.
One of the biggest changes made by the ending of Crisis on Infinite Earths erased a major death from the show’s canon. In Arrow season 2, Slade, still reeling from Oliver’s failure to save Shado (Celina Shade) on Lian Yu, forced Oliver to make an impossible choice. He wanted Oliver to choose between saving Moira and saving Thea (Willa Holland). Moira made the choice for him, and was subsequently killed by Deathstroke. But in the new reality seen in the Arrow series finale, a flashback revealed that Oliver managed to free himself at the last second and save Moira. Due to this change in the timeline, Moira is alive and well, and was able to attend Oliver’s funeral in the finale.
The finale explored what this pivotal season 2 moment being altered meant for Moira, but what did it mean for Deathstroke? The Arrowverse hasn’t provided a clear answer, since he hasn’t been around since he last teamed up with Oliver Queen in season 6. However, some conclusions can be drawn based on what happened after Moira’s death in season 2. As dangerous as Deathstroke was with Mirakuru running through his veins, it’s likely that he was still locked away on Lian Yu, even if he didn’t kill Moira. Barry (Grant Gustin) and Diggle’s visit to the prison on Lian Yu in The Flash season 6 revealed that he’s no longer being held there, which would suggest that just like the original version of the timeline, he was released to help out in the fight with Prometheus (Josh Segarra).
In Arrow seasons 5 and 6, Deathstroke expressed regret for what he did, and a willingness to do better in the future. Oliver forgave him because he understood that despite everything that happened between them, Slade wasn’t in full control of his actions. It was the Mirakuru that made him act irrationally. Slade not killing Moira wouldn’t make this much different, but it could have made his path easier in some ways. It at least would have lessened the guilt he felt toward Oliver, but its worth noting that Deathstroke did kill innocent guards and other people who got in his way in season 2. Regardless, Slade still has a lot of deaths on his conscience.
Deathstroke’s place in the Arrowverse could still be in the same as it was when he left in season 6. He’s likely out there somewhere, possibly still searching for his sons. But with Arrow over, viewers may never get to see Deathstroke’s post-Crisis fate. Even if DC does allow the CW to use Deathstroke again, none of the current shows feel like an obvious new home for the character, but it could be that an older version of Slade Wilson will emerge on Green Arrow and the Canaries if the show is ever picked up.