Nihilistic Seraph
Completely off topic, save for the references in the website. Ah! My Goddess, by Kosuke Fujishima (Artist of Tales of Symphonia razz ) has the three sisters, Uld(past), Skuld(futur) and Belldandy(present). On a side note, there is also an Yggdrasil in Tales of Symphonia, but that's another story.