Whedonverse Appearances: Firefly/Serenity as Dr Simon Tam; Much Ado About Nothing as Don John.
DC Appearances: Arrow as Mark Scheffer/Shrapnel; Son of Batman as Nightwing/Dick Grayson; Batman vs Robin as Nightwing/Dick Grayson; Batman: Bad Blood as Nightwing; Justice League vs Teen Titans as Nightwing; Teen Titans: The Judas Contract as Nightwing.
Firefly star Sean Maher has become the go-to voice actor for Batman’s former sidekick Nightwing in recent years, as he has portrayed the character across various straight-to-DVD animated movies since 2014. That same year, he also appeared in a couple of episodes of Arrow.
Whedonverse Appearances: Buffy the Vampire Slayer/Angel as Drusilla.
DC Appearances: Justice League Unlimited as Tala/Zatanna Zatarra, Green Lantern: First Flight as Labella, Justice League: Doom as Ten, Green Lantern: The Series as Drusa, Justice League: Throne of Atlantis as Lois Lane/Cassie Sandsmark.
Juliet Landau – AKA insane vampire Drusilla – has voiced several DC characters, sometimes different roles in the same production. Most notably, the sorceress superhero Zatanna and Superman’s girlfriend Lois Lane.
Whedonverse Appearances: Angel as Prima Ballerina, Firefly/Serenity as River Tam, Dollhouse as Bennett Halverson.
DC Appearances: Superman/Batman: Apocalypse as Kara, Arrow as Isobel Roschev.
Summer Glau is one of Whedon’s recurring favourites, and she has also turned up a couple of times in the DC universe. First as Superman’s cousin Kara AKA Supergirl in an animated movie and then she appeared in the flesh in several episodes of Arrow‘s second season.
Whedonverse Appearances: Angel as Jasmine, Firefly/Serenity as Zoe Washburne.
DC Appearances: Justice League Unlimited as Mari McCabe/Vixen, Justice League: Crisis on Two Earths as Superwoman, DC Universe Online as Wonder Woman.
Firefly star – and Angel big bad – Gina Torres has managed to voice two of DC’s major superheroines. She recurred as animal-channelling Vixen on JLU and then voiced an alternate, evil version of Wonder Woman in straight-to-DVD movie Crisis on Two Earths. Torres then played the actual Amazonian princess in an online video game.
Whedonverse Appearances: Angel as Winifred ‘Fred’ Burkle/Illyria, Dollhouse as Dr Claire Saunders/Whisky, The Cabin in the Woods as Lin, Much Ado About Nothing as Beatrice, Agents of SHIELD as Audrey Nathan.
DC Appearances: Justice League Unlimited as Helena Bertinelli/Huntress.
I think it’s pretty clear by now that the makers of the DC Animated Universe were massive Whedon fans. Amy Acker appeared in four episodes of JLU as the vigilante Huntress. I don’t know about you, but I think she would make a terrific Helena in a movie version, too.