Claire Redfield's from Capcom's Resident Evil, Yuna and Rikku are from Square Enix's Final Fantasy X-2 and this screenshot's taken from Valve's Garry's Mod.

Yuna and Rikku were walking around some place to check out many alternate universes and, of course, the Multiverse, until they just saw Yuna's dark version from her own universe fighting Claire from hers, who, once upon a time, became zombified, in other words, forever undead. during one of her missions helping out Tifa and her adoptive family. They're both shocked about this crazy situation.