History ComicBook / BatmanSupermanWorldsFinest

* SemanticSuperpower: Parasite is able to absorb sources of energy to sustain himself as a PowerParasite. While he typically does this to life energy and superpowers, he learns from a fifth-dimensional imp that this is just the tip of the iceberg. Parasite learns how to absorb the energy from atomic bonds to break any restraint before absorbing the volume and mass of his victims, reducing them to 2-D images. [[spoiler:He leaves Superman, Batman, and Robin as street art on a nearby wall at the end of Issue #26.]]

* TheBusCameBack: In Issue #11, The Key brings several practically unknown villains to deal with Superman and Batman. They are Zebra Man, Bag o'Bones, Ferlin Nyxly, Dr. Phoenix the Abominable Snowman, and Acid Master. While the first one had a supporting role on the ''Suicide Squad'', and the second one became an Outsiders villain, the others hadn't appeared in decades (Vyndktvx from ''ComicBook/ActionComicsNew52'' was loosely based on Nyxly, but is a very different character).

* CallForward: In issue #14, when trying to figure out who killed Simon Stagg, Robin says that Bruce wouldn't kill anyone so forward, he'd probably hire someone to do it, someone with a personal grudge. This is basically the plot of ''ComicBook/BruceWayneFugitive''.

* TheBusCameBack: In Issue #11, The Key brings several practically unknown villains to deal with Superman and Batman. They are Zebra Man, Bag o'Bones, Ferlin Nyxly, Dr. Phoenix the Abominable Snowman, and Acid Master. While the first one had a supporting role on the ''Suicide Squad'', and the second one became an Outsiders villain, the others hadn't appeared in decades (Vyndktvx from ''Comicbook/ActionComicsNew52'' was loosely based on Nyxly, but is a very different character).

* CompositeCharacter: The final splash of issue #24 shows post-''Comicbook/KingdomCome'' heroes of Earth-22, including some kind of multi-elemental that looks like Metamorpho combined with Swamp Thing, and a figure in what appears to be a Batman Beyond costume with a Nightwing mask and an "R" insignia.

** Issue #18 is an entirely new "first meeting" between the two heroes, but includes a brief appearance by Magpie, from the continuity-before-last's first meeting in ''Comicbook/TheManOfSteel'', and Spellbinder, who in pre-Crisis continuity fought Batman and Superman separately.

** In #20, Superman discovers that Earth-22 has no record of any encounters with beings from another universe. This possibly reflects that it was originally a possible future, not of Earth Prime, but of New Earth prior to ''Comicbook/InfiniteCrisis'', when DC's official policy was that there ''were'' no alternate universes, or simply that in the period of it that they are visiting, the stories where they interact with other timelines (''[[ComicBook/TheKingdomDCComics The Kingdom]], [[ComicBook/JusticeSocietyOfAmerica Thy Kingdom Come]], [[ComicBook/SupermanBatman Absolute Power]], ComicBook/InfiniteFrontier'', etc.) had not yet ocurred from either world's perspective.

* NarniaTime: The relationship of time between Prime Earth and Earth-22 is weird, possibly because Earth-22 only exists as a "near future". When Superman and Batman travel there, they initally find themselves at the ''end'' of ''Comicbook/KingdomCome'', before bouncing back to some years prior to it, which arguably makes more sense. What's been "a few months" for them has still been long enough for Boy Thunder to become Thunderman, though.

* PowerIncontinence: David accidentally lights a forest ablaze when he develops his powers after arriving on the main Earth. A combination of the stress from losing his world and suddenness of his abilities prevents him from controlling them until Superman uses his Super Breath to cool David off and helps him calm down.

* SeriesContinuityError: "Heir to the Kingdom" kicks off when Barry Allen finds the ''Comicbook/KingdomCome'' universe during his regular mapping of the "thousands and thousands" of worlds in the multiverse. This takes place "a few months" after "Strange Visitor", but current continuity has it that Earth Prime only learned there were more than 51 other Earths, and Barry started exploring them, during ''Comicbook/DarkCrisis''.

Beginning in July 2023, Waid and Emanuela Luppachino will launch a [[ComicBook/WorldsFinestTeenTitans spinoff book]] focusing on the classic Teen Titans and likewise set in the not-too distant past.

* TheBusCameBack: In Issue #11, The Key brings several practically unknown villains to deal with Superman and Batman. They are Zebra Man, Bag o'Bones, Ferlin Nyxly, Dr. Phoenix the Abominable Snowman, and Acid Master. While the first one had a supporting role on the ''Suicide Squad'', and the second one became an Outsiders villain, the others hadn't appeared in decades.

* ContinuitySnarl: There are a lot of names on the graves in Issue #20 that show characters that weren't supposed to have died in the Gulag battle, including Red Robin and Green Lantern. The story still isn't finished yet, so it may turn out to be foreshadowing.

* {{Prequel}}: Generally takes place in a fusion of Silver Age and Bronze Age eras DC Universe during the period where Dick Grayson was still Robin instead of Nightwing. Batman and Superman are BFFs who regularly hang out together and show next to no hostility of the later versions

* RevengeByProxy: When Batman uses defoliant to counter Poison Ivy's murderous vines, the latter roars "You kill something dear to me-- I'll do the same!" before trying to throw Robin off a rooftop.

* AloneWithThePsycho: Nezha's containment chamber can only be locked from the inside, making a HeroicSacrifice necessary.

* {{Prequel}}: Generally takes place in a fusion of Silver Age and Bronze Age eras DC Universe during the period where Dick Grayson was still Robin instead of Nightwing.

** Issue #18 is an entirely new "first meeting" between the two heroes, but includes a brief appearance by Magpie, from the continuity-before-last's first meeting in ''Comicbook/TheManOfSteel'', and Spellbinder, who in pre-Crisis continuity fought Batman and Superman seperately.

** In #20, Superman discovers that Earth-22 has no record of any encounters with beings from another universe. This possibly reflects that it was originally a possible future, not of Earth Prime, but of New Earth prior to ''Comicbook/InfiniteCrisis'', when DC's official policy was that there ''were'' no alternate universes.

** In the same issue, when Bruce tells Clark he's deduced his identity, he matter-of-factly reveals his own, saying there wasn't much point in trying to keep it secret unless he wore a lead-lined cowl. When Batman tells Superman he'd deduced his identity in ''Adventures of Superman'' #440, he ''is'' wearing a lead-lined cowl (it doesn't help).

* PrototypeVsUpgradeFight: [[spoiler:To defeat [=NewMazo=], Batman's able to find and activate a spare Amazo robot and send him after [=NewMazo=]. Though [=NewMazo=] comes out on top, he's damaged enough for Metamorpho to finish the job]].

* StartOfDarkness: The "Strange Visitor" storyline is this for [[spoiler:[[ComicBook/KingdomCome Magog]]]].