As Slade reels about the truth about his son, Team Arrow contends with a new player in the Star City Underground — Ricardo Diaz.
- Ambiguous Situation: It's not entirely clear if Grant is a product of Flashpoint, or if he always existed; after all we saw him and John Jr. before Flashpoint.
- Antagonistic Offspring: In the end, Joe is just as far gone as Slade was during Season 2, even without the Mirakuru, to the point where he even tries to kill his father.
- Arc Words: Appropriately for a Slade-centric episode: "promise" and "promises".
- Awful Truth: In the climax, Slade learns that Joe saw him kill that Chinese spy during their camping trip all those years ago, and promptly made his first kill six months later. Slade originally believed that Joe was trying to emulate the person he was under the effects of the Mirakuru — this revelation makes him realize that Joe always saw him as that person, and with that he loses any will he had to continue the fight.
- Bait-and-Switch:
- At first it seems like Slade actually wants to kill Oliver at the behest of his son....only to cut through the restraints. He even admits to Oliver that he was seriously contemplating it, to his own shock and horror.
- Curtis is disappointed that Diggle... didn't come to him for help about his tremor. After all, he helped Felicity walk again.
- Bittersweet Ending: On the plus side, Diggle has come clean to the team about his injury and is getting Curtis' help with it, while Oliver and Slade managed to stop the Jackals' plan. On the other hand, any chance Slade had at rebuilding his relationship with Joe has been lost and both Joe and Dragon escaped despite their defeats. Also, Slade learns that it was emulating him that led his son to become the violent criminal he is now, in addition to discovering that he has another son that he's never known, leaving him a broken man whose only hope of reuniting with his family may be doomed to failure if the future of "Star City 2046" comes to pass.
- Bloodbath Villain Origin: While he was already well on his way, the incident that sets off Slade's time as Deathstroke is marked by him slaughtering several ASIS commandoes with a katana.
- Book Ends: When Slade and Oliver first went into combat together in "The Odyssey" , Slade took down ten mercenaries single-handed, then arrived Just in Time to save Oliver from being killed by the single mercenary he was supposed to deal with. This time Oliver takes on all the Jackals by himself, then turns up Just in Time to save Slade from being killed by his son.
- The Bus Came Back: Shado, or rather Slade's imaginary Shado, comes back via flashbacks.
- But Now I Must Go: Slade leaves to find both his sons — Grant and Joe.
- Call-Back:
- In the Season Five finale, Slade gave Oliver a much needed talk about his Survivor's Guilt over his father's death. In this episode, Oliver returns the favor, convincing him not to give up on Joe being redeemed, seeing as Slade redeemed himself for far worse things, enough that Oliver even forgave him for it.
- Also from that episode, Oliver mentions how Slade pretended to switch sides to fool Chase, though on this occasion Slade really was tempted to do so.
- Celebrity Paradox: Felicity and William are seen playing Injustice 2.
- Chronic Hero Syndrome: When Slade once again tells Oliver to go home, the latter responds that he won't leave Slade behind and can't just walk away after seeing what the Jackals are capable of.
- Continuity Nod: Several, given that the flashbacks in the episode effectively serve as an Origin Story for Deathstroke.
- The Australian rum that was a prominent element in the Season 2 episode The Promise makes a reappearance in this episode, in both the present day and the flashbacks.
- Slade is shown training his son (now an ASIS trainee) in stickfighting and calling him "kid", referring to the Parental Substitute relationship he had with Oliver.
- The old "Oliver Queen is alive" news report from the pilot also makes an appearance in the flashbacks.
- In the flashbacks, Slade has PTSD-induced flashbacks to his time on Lian Yu with Oliver, as well as their battle on the Amazo.
- "Could Have Avoided This!" Plot: Curtis even lampshades that he is smart enough to build a device that enabled a paralyzed woman to walk again, so John could have come to him to get help with his tremor from the beginning.
- Dark Reprise: When Joe throws down the flashbang to escape from his father and Oliver, we hear a snippet of "Never Again
", the theme for the Final Battle between Oliver and Slade from the season 2 finale. - Dark Secret:
- Slade went home to Joe after he was rescued, and promised him he would stay.. but the Mirakuru came back with a vengeance. He tried to fight it, but when he saw Oliver was alive...
- Joe reveals he saw Slade kill the Chinese spy on the camping trip, and six months later made his first kill trying to emulate his father.
- Dropping the Bombshell: Joe reveals he has a brother Grant; Slade's wife kept him a secret because he didn't want him to follow in his father's footsteps. Looks like the future of Star City the Legends saw is now all but inevitable. But since the future is constantly in flux, who knows?
- Drugs Are Bad: Sorry, John. Even if said "drugs" are actually a neuropathic steroid that's helping with your debilitating hand tremors and is not narcotic or addictive in any way, people will still treat you as if you're a lowlife junkie for taking medicine to manage your degenerative nerve damage.
- Easily Forgiven:
- After coming out with it, everybody is quick to forgive John for taking drugs against his tremor.
- When Joe demands to know how his father could forgive Oliver Queen for putting out his eye and leaving him for dead, Slade points out that Oliver has forgiven him for far worse crimes.
- Even Evil Has Loved Ones: Even after he goes insane and slaughters his fellow ASIS agents, Flashback!Slade doesn't kill his son.
- Excessive Steam Syndrome: While it looks cool, there's no real rhyme or reason for the jets of steam that Slade walks through as he exits.
- Hypocrite:
- Lyla considers Diggle one after he tries to use the "Ends Justify the Means" excuse he lectured her on last year. To his credit, he fully admits it at the end of the episode.
- Immediately after Dinah agrees with John that there should be no more secrets between them, she takes out the gift that Vincent Sobel/Vigilante left her in the last episode, obviously concealing that she let him go.
- If You're So Evil, Eat This Kitten!: Joe orders his father to kill Oliver as proof that he is one of them. Slade draws his sword and cuts Oliver bonds instead so they can escape, but admits afterwards that he was tempted to kill Oliver if that was what it took to reconcile with Joe.
- I Gave My Word: After he escapes from Lian Yu, the effects of the Mirakuru have apparently faded and Slade promises to never leave his son. Unfortunately a year later the hallucination of Shado returns to remind Slade of the promise he made to avenge her.
- I Have No Father: When Slade states he is no longer Deathstroke and lays down his sword during his duel with his son, Joe disowns him and promptly tries to kill him.
- I See Dead People: In the flashbacks, Slade, still under the effects of the Mirakuru, keeps seeing Shado, egging him to kill Oliver.
- Improbable Aiming Skills: Oliver manages to shoot the sword out of Joe's hand with a handgun.
- Internal Reveal: Diggle tells Lyla about his tremor and the drugs he's taking to fix it. At the end he tells Team Arrow the truth about everything that's been going on.
- Karma Houdini: Both Joe as well as his second-in-command Nylander make it out alive at the end of the episode.
- Keeping Secrets Sucks: John promises Dinah that there will never be secrets between them ever again. Ironically, she is then seen holding her trinket left to her by Vigilante.
- Leave No Witnesses: Joe's policy, as he mercilessly executes one man Slade merely shot in the leg.
- Like Father, Like Son: To Slade's deepest regret, Joe has become just like him at his worst.
- Mistreatment-Induced Betrayal: How Joe justifies running the Jackals; ASIS left him for dead. In truth however, he feels betrayed by Slade for leaving him to seek vengeance on Oliver, after he promised he would stay.
- Morality Chain: Slade was tempted to kill Oliver if that's what it took to reunite with Joe, but Oliver mentioning William stopped him.
- My God, What Have I Done?:
- Diggle is aghast that the steroids he's been taking aren't experimental drugs waiting to be FDA approved but designer drugs to be dealt on the street.
- Slade is horrified to learn that his son's criminal path started when he saw Slade murder a Chinese agent while they were on a camping trip.
- Mythology Gag: Joe reveals his first kill was a Slashed Throat, something inflicted on him in his comic counterparts backstory.
- "Not So Different" Remark: After revealing that he has been taking drugs for his tremor, Diggle tries to invoke this on Lyla, claiming that she too would do anything to get the job done. Lyla however reminds John that he himself told her that the ends don't justify the means.
- Origins Episode: The flashbacks of this episode serve as one for Deathstroke - revealing what happened to Slade between the battle on the Amazo, and his crusade against Oliver in Season 2.
- Pop the Tires: The Jackals use a spike strip to run the truck carrying the Semtex off the road.
- Put on a Bus: Slade leaves at the end of the episode, as Joe is still on the loose and he now has a second son to find.
- The Reveal:
- Slade got his Deathstroke battle armor from the ASIS training facility.
- Where has Diggle been getting his steroids to keep his tremors in check? Ricardo Diaz.
- Revenge by Proxy: After hearing that Oliver has a son, Joe proposes to his father to kill him for revenge too.
- Sanity Slippage: The flashbacks track Slade's descent into the insanity that defined his character in Season 2. It starts with flashbacks to Lian Yu, then he starts seeing Shado, and he finally snaps completely after realising that Oliver is still alive.
- Terrorists Without a Cause: The Jackals plan to destroy the water treatment plant that supplies most of the country's water, but it's not said who this benefits.
- That Man Is Dead:
- When Slade calls his son "Joe", he claims that it's not his name anymore, but doesn't raise further objections when Slade keeps calling him that.
- Slade himself rejects the identity of Deathstroke, no longer seeing that as who he is since he's been cured of the Mirakuru and wants to atone for his actions.
- Thousand-Yard Stare: Diggle when Dragon torches his stash of steroids.
- Trauma Button: After Slade comes home from Lian Yu, he runs into tons of these as he tries to move on with his life. The biggest one is when he sees the news headline that Oliver is alive.
- What Have I Become?: Diggle realizes how far he's fallen when he realizes he was fully tempted to run into the flames to get as much of Dragon's drugs as possible.
- What the Hell, Hero?: Lyla is rightfully disgusted that John wants to keep Dragon on the streets until ARGUS can come up with something to fix his tremor.
- You Are Better Than You Think You Are: Oliver gives Slade another one of these speeches, emphasizing that he was a good man before the Mirakuru and that he needs to show that to his son.
