Actors that have played both #DC and #Marvel characters
#TomHardy has played both a DC villain and Marvel Hero (antihero)
Tom Hardy in DC as villain #Bane
Tom Hardy in Marvel as antihero #Vendom
#MichaelKeaton has played a DC hero and a Marvel villain
Michael Keaton in DC as hero #Batman
Michael Keaton in Marvel as villain #Vulture
#BenAfflect has played a hero in both Marvel and DC
Ben Affleck in Marvel as #DareDevil
Ben Affleck in DC as #Batman
#JaredLeto has played both a DC villain and Marvel hero
Jared Leto in DC as the #Joker
Jared Leto in Marvel as #Morbius #DrMichaelMorbius
#RyanReynolds has played heros in both DC and Marvel
Ryan Reynolds in #DC as #GreenLantern #HalJordan
#HalleBerry has been a hero in both Marvel and DC
Halle Berry in Marvel as #Storm #Mutant #Xmen
Halle Berry in DC as #Catwoman
#SylvesterStallone has been in both Marvel and DC
Sylvester Stallone in #Marvel as #StakarOgord
Sylvester Stallone in #DC as #KingShark
#MichaelRosenbaum as played a villain in DC, a hero in DC and in Marvel
Michael Rosenbaum in #DC as #LexLuther
Michael Rosenbaum in #DC as #TheFlash #Flash #DCAnimatedUniverse
Michael Rosenbaum in Marvel as #Martinex
Michael Rooker #Marvel and #DC
Michael Rooker in Marvel as #Yondu
Michael Rooker in #DC as #Savant
that's all I can think of at the moment. :)