History Recap / TheFlash2014S9E9ItsMyPartyAndIllDieIfIWantTo

* CrisisCrossover: A variation. With the return of Oliver and Diggle, this episode will serve as one last team-up between ''Arrow'' and ''The Flash'' (and for all intents the final Arrowverse crossover, albeit more in line with Season Eight's "Armageddon").

* LampshadeHanging: When Oliver clarifies which alternate Earth the Red Death is from by number, Barry is incredulous that he's been numbering the realities in the new multiverse. Oliver just says he's had a lot of time on his hands.

* BackForTheFinale: A variation. With the Arrowverse's adventures on Earth-Prime concluding with the final season of ''The Flash'', Creator/StephenAmell returns to the franchise his show launched one last time (as does Creator/DavidRamsey for Diggle's final apperance). Likewise, Creator/KeiynanLonsdale returns to ''The Flash'' for Wally West's Arrowverse swansong.

* {{Bookends}}: Barry made his first Arrowverse [[Recap/ArrowS2E8TheScientist appearance]] on Oliver's show. Oliver, likewise, now makes his final Arrowverse appearance on Barry's show. Oliver also says that Barry is running through his city like a guardian angel, bringing hope, and that the bolt of lightning did choose Barry -- [[Recap/TheFlash2014S01E01Pilot just what he said all those years ago]].

* {{Bookends}}: Barry made his first Arrowverse [[Recap/ArrowS2E8TheScientist appearance]] on Oliver's show. Oliver, likewise, now makes his final Arrowverse appearance on Barry's show. Oliver also says that Barry is running through his city like a guardian angel, bringing hope, and that the bolt of lightning did choose Barry--just what he said all those years ago.

* TheReveal:
** Ever since ''Crisis'', many speculated whether Oliver was DeaderThanDead or if he retained his Spectre powers, allowing him to return if needed. This episode definitively answers that question: he can indeed, but there is one limit to his powers, in that he cannot interact with Felicity or his children in any way, so as to keep the timeline leading up to Felicity joining him in the afterlife intact. He also mentions that he can only get involved during multiverse-level threats, explaining why he hasn't made contact with any of his allies until now.
** Turns out the Red Death is not from an alternate timeline as previously claimed, but from Earth-4125.

* TragicKeepsake: A.R.G.U.S. has recovered Oliver's old bow from where he died in National City, which Diggle wants to give to Barry. Barry thinks it would be fit better in the Hall of Justice.

* WorfHadTheFlu: As the Spectre, Oliver is one of the most powerful beings in the multiverse. However outside some of abilities, he's BroughtDownToBadass again when fighting Bloodwork due to his attack on the multiverse weakening his powers.

** Cecile also states that Barry’s last 30th was derailed by [[NoodleIncident a battle with Cicada]].

* CallBack: Oliver and Barry reminisce back to when they first met.

* MythologyGag: The "Flash Facts" are a reference to a CatchPhrase from the comics where a Flash would express a scientific fact relevant to a ploy he's about to pull off.

* {{Bookends}}: Barry made his first Arrowverse [[Recap/ArrowS2E8TheScientist appearance]] on Oliver's show. Oliver, likewise, now makes his final Arrowverse apperance on Barry's show. Oliver also says that Barry is running through his city like a guardian angel, bringing hope, and that the bolt of lightning did choose Barry--just what he said all those years ago.

* LeaningOnTheFourthWall: When Ramsey places Barry in a mock-up production room and tells him that he is the star of the show.

* MythologyGag: The "Flash Facts" are a reference to a CatchPhrase where a Flash would express a scientific fact relevant to a ploy he's about to pull off.

* LightningLash: Oliver and Barry use their lightning to form whips, holding Ramsey in place for Oliver to take the shot.

* TamperingWithFoodAndDrink: Ramsey spikes the drinks with his blood, infecting most of the party guests.

* HarmlessFreezing: Despite Khione freezing their blood, nobody of the infected are worse for wear afterwards.

** Ever since ''Crisis'', many speculated whether Oliver was DeaderThanDead or if he retained his Spectre powers, allowing him to return if needed. This episode definitively answers that question: he can indeed, but there is one limit to his powers, in that he cannot interact with Felicity or his children in any way, so as to keep the timeline leading up to Felicity joining him in death intact. He also mentions that he can only get involved during multiverse-level threats, explaining why he hasn't made contact with any of his allies until now.

** Ever since ''Crisis'', many speculated whether Oliver was DeaderThanDead or if he retained his Spectre powers, allowing him to return if needed. This episode definitively answers that question: he can indeed, but there is one limit to his powers, in that he cannot interact with Felicity or his children in any way, so as to keep the timeline leading up to Felicity joining him in death intact. He also mentions that he can only get involved during multiverse level threats, explaining why he hasn't made contact with any of his allies until now.

* AllPowerfulBystander: Oliver is only allowed to intervene when the Multiverse is in danger.

** Since the Multiverse is in danger, Oliver briefly returns to the world of the living, following the ending of ''Arrow'' and his death during ''Crisis on Infinite Earths'' and "Fadeout".

* ABirthdayNotABreak: Barry's birthday party is rudely interrupted by the reappearance of Bloodwork, who is plotting to take over the Multiverse.

* TheCorrupter: Ramsey has his sights on Wally, sympathizing with him over his past hardships and promising him that [[WeCanRuleTogether he can be part]] of a Multiverse without death.
* CrisisCrossover: A variation. With the return of Oliver and Diggle, this episode will serve as one last team-up between ''Arrow'' and ''The Flash'' (and for all intents the final ''Arrowverse'' crossover, albeit more in line with Season Eight's "Armageddon").

* EpisodeOfTheDead: Since the villain is Bloodwork, this is at play again, with most of the cast becoming infected by him and him even setting his sight on the entire Multiverse.

* InternalReveal: Barry finally learns that the Multiverse was restored at the end of ''Crisis of Infinite Earths''.

* MultiversalConqueror: While he previously only wanted to infect the world, with the help of Wally Ramsey sets his sight on the entire Multiverse this time, wanting to give everyone across it eternal life.

* TragicKeepsake: Diggle still has Oliver's old bow, which he wants to give to Barry. Barry thinks it would be fit better in the Hall of Justice.