The Elfrica Game Over is an ending which occurs if the party loses to Rania in Rania's Fun House.
Disappointed in your showing up, Rania declares you all to be boring. Deciding to play with you all and have her own fun, Eric(a) is frozen in place as the mad mage turns to deal with the rest of the party first.
Natalie attempts to protest first but, barely getting a few words out, Rania decrees that demons are boring and quickly banishes her back to Hell. Alice then proceeds to attack, demanding for Rania to summon Natalie back, but she is quickly subdued with Rania beginning her transformation into a cowgirl. With Veronica prepared to go down fighting, she is instead turned into a terrified coward, who under threat of being sent to the Exile Dimension is instead to be turned into a ponygirl and trained so as to be added to the stable of a pervert who Rania knows. Feeling tired, she finally decides to just erase Eric(a) from existence, to the point that not even any memories would remain for them to be mourned by.
Later feeling bored once more, Rania regrets to have erased Eric(a) so quickly. Realizing that their soul still exists, she decides to recreate Eric(a) and have a bit of fun while at it. As a result Eric(a)'s soul is reconstituted once more, taking the form of a cute little sister for Rania named Rydia. Seemingly having been created with a full memory of an previous history, she slips into her new role seamlessly. Rania is especially delighted by Rydia's responsible personality, who is in turn rather dismayed and worried by Rania's manic behaviour which she notes as having begun after finding a particular mirror.
With Rania prepared to set out on a new adventure, Rydia insists on following along to keep her out of trouble. All sorts of crazy adventures follow, the most serious problems kept under control by the responsible little sister Rydia. Eventually she even frees Rania from the mirror's influence.
All of this though is the story of Rania and Rydia. Eric(a) as they once were has long since ceased to exist.