History Recap / Supergirl2015S1E18WorldsFinest

* SuperStrength: Silver Banshee somehow gets this in addition to her trademark [[MakeMeWannaShout sonic scream]]; at one point she is inexplicably able to send Supergirl flying with a single punch.

--->'''Kara:''' Do you like donuts?\\

* CryCute: The normally proud Cat tearfully begs for her life. [[TearJerker Not for herself, but for her sons to still have a mother.]]

* AbsenteeActor: Neither Chyler Leigh nor Creator/DavidHarewood appear in this episode, in each case marking their first absences of the series. Both, however, still receive screen credit (and are seen in the recap which explains the reason for their absence).

** Since Arrowverse Earth is Earth-1, Zoom is from Earth-2, and Jay Garrick is from Earth-3, none of whom are known here, this makes Kara's Earth Earth-38, the year of Superman's first appearance in the comics.

* HighConcept: PlayedForLaughs with Supergirl pretty much saying her general ''modus operandi'' when describing her "[[IndyPloy plan]]" to catch Livewire and bring her back to the DEO.
-->'''Supergirl:''' Catch a bad girl, bring her back here so she can't hurt anyone, 85% chance of punching.

* AdaptedOut: It has been confirmed that none of the members of Team Flash exist in this universe, although them having different names is possible (as ''The Flash'' shows with Jay Garrick & Henry Allen).[[note]]Since there are three Killer Frosts in the comics, the door is open for Crystal Frost and/or Louise Lincoln to appear in the future.[[/note]] As for the members of Team Arrow, if any of them exist in this universe they haven't assumed their superhero identities.

** Many superheroes present in the Series/{{Arrowverse}} but not here are mentioned in this universe for the first time, such as ComicBook/GreenArrow, ComicBook/BlackCanary, ComicBook/{{Firestorm}}, and ComicBook/TheAtom. Barry also mentions Zoom, the current BigBad of his series.

* {{Adorkable}}: Kara and Barry, in spades, with Kara upping the ante with her reaction to the ice cream cone stunt and promising Barry that there will be "85% chance of punching" when they go after Livewire.

** The "Elseworlds" crossover showed that James Olsen and Alex Danvers exist on Earth-1; however, James' occupation is unknown (he is working as hired muscle for Cisco Ramon) but Alex is working for Earth-1's DEO, which is apparently a more secretive organization.

** Flash namedrops the Pied Piper when explaining how he knows how to counter sound-based villains. Non pulls a Pied Piper trick of his own at the end. (And Pied Piper plays a role in the first ''Flash'' [[Recap/TheFlash2014S2E17FlashBack episode to air]] after the crossover.)

* WhamEpisode: This episode officially makes the show part of Series/ArrowVerse {{multiverse}}.

* OpenSecret: It would appear that the DEO doesn't seem to care if its "secret base" is secret anymore. Winn and James appear able to come and go at will, and Kara has no problem bringing Barry into the base before Lucy is even aware of his presence. But the icing on the cake is that Winn is able to bring Siobhan into the base; even though her presence isn't unusual, as the DEO would have a vested interest in examining her, it does kind of blow any secrets Winn might be carrying about his involvement with the organization.

** Additionally at the end Barry calls Kara the 'Girl of Steel', and she returns the favour by referring to him as the 'Scarlet Speedster'