Arrow: 7 Plot Threads The Show Totally Abandoned

7. Deathstroke's Search For His Other Son

Slade Wilson's return in Arrow's Season 5 finale brought with it a highly-compelling two-parter in which Oliver's former enemy attempted to track down his son Joe Wilson. Upon doing so, he learned that his beloved son had become a mercenary - but as upsetting as that was for him, it wasn't the biggest shock he received that day, as he also learned that he had another son: Grant Wilson.

While we had met an alternate version of Grant on DC's Legends of Tomorrow, the reference to him here suggested that he was going to make his debut in the main timeline of Earth-1 - but not before Slade went off to track him down.

However, Grant did debut in Season 8 - with Jamie Andrew Cutler reprising his role - as the leader of a preliminary version of the Deathstroke Gang. As this was little more than a plot device to force the time-traveling Team Arrow kids to be honest to their fathers, there was no time spent on giving Grant a backstory. Naturally, we're all left wondering if Slade ever found him in the two years prior...

As Crisis On Infinite Earths more than likely undid all of that, we may never know...