Also known as: イプシロン(Fate)
A character in Fate/Grand Order, resembling Typhon Ephemeros (Fate)' first ascension but with Blue Hair and Blue Eyes. It's available as a costume dress for Typhon Ephemeros.
In the Rakurui No Tsubasa event, it is revealed that due to Ephemeros's anti-wish nature, she wished for Epsilon to be created to allow wishes to be made. To prevent the wish from from being rejected, Ephemeros would then completely forget about Epsilon.