Without a doubt, this generation's Liss was a sister laden with many flaws.
Primarily because Diya hadn't encountered many people; her database consisted of either the Mage's Handbook or fairy tales. Alas, having crossed over, she was immediately captured by the Four Pillars God Sect, so Diya could only model her hastily created sister after the protagonist she read about in the fairy tale "Little Witch," crafting a sibling who matched the age and appearance.
Thus, Little Witch Liss was born.
In actuality, "Lissdia" was not a name but two "positions." Whoever was responsible for controlling the body in reality assumed the name "Liss"; whoever took action in the Void Realm became "Diya."
Their true names were actually Little Witch, Secret Princess, Black Butler, White Queen, Red Death Cultist, and so forth. Generally speaking, actions within the Void Realm were primarily undertaken by the Secret Princess, so the name "Diya" was almost exclusively associated with her.