American Batman is played by Irish actor Jason O'Mara.
Method Acting: According to Jay Oliva at Comic-Con, Luddington actually pronounced the words backwards for when Zatanna cast spells herself.
Missing Trailer Scene: The page quote isn't actually in the film, as Batman is dismissive of magic even being the cause. He only goes looking for Constantine because Deadman paints the name all over his room and then insists Zatanna arrange a meeting when Batman goes looking for answers.
The Other Darrin: The Latin American Spanish dub suffers one in a meta-sense: Unlike almost all of the DC Universe Animated Original Movies, which were dubbed in Venezuela since day one, this one was dubbed in Mexico instead, very likely because the socioeconomic crisis Venezuela is suffering right now (as of 2020) has made dubbing in that country a very difficult feat.
Not only did Matt Ryan reprise his role as John Constantine from Constantine, but Jeremy Davies also reprised his role of Ritchie Simpson from that same show.
In the French dub, in addition to having the same role reprisals from Justice League vs. Teen Titans, three more voice actors from previous adaptations also reprised their roles here:
From Arrow: Axel Kiener as John Constantine.note As of this writing, Constantine has never been dubbed in French, unlike the other series set in the Arrowverse.
to record his dialogue as John Constantine. That's dedication.