|Anime debut||Yu-Gi-Oh! ARC-V episode 116: "A Towering Achievement"|
Diana is a lilac-haired pale-skinned woman who dresses in Roman attire. She wears white robes with a golden chain tied at the shoulder, blue armguards, and brown sandals with thick soles, in addition to a golden crown white the shape of a crescent moon on each side with cloth shielding the nape of her neck. Her crown shadows her eyes, and she carries a golden staff with a crescent moon symbols as the head, set with a blue gem.
Diana is named after the Roman goddess of the moon.
Kite Tenjo arrived at the top of the Western Tower to rescue Lulu Obsidian, and Diana told Kite to Duel her if he wanted to rescue Lulu. She Fusion Summoned "Penumbral Keeper" and activated its effect to Special Summon a "Keeper Shield Token". When Kite brought out "Galaxy-Eyes Cipher Dragon", Diana activated "Admiration of the Keepers" to negate the effects of "Cipher Dragon", Special Summon two "Keeper Shield Tokens", and force "Cipher Dragon" to attack all "Keeper Shield Tokens" or be destroyed at the end of the Battle Phase. When "Cipher Dragon" destroyed all the "Keeper Shield Tokens", Diana activated the effect of "Penumbral Keeper" to decrease the ATK of "Cipher Dragon" and increase her own LP by 800. As Diana brought the ATK of "Cipher Dragon" down to 600, she wondered if there was any point for it to remain on the field until Kite brought out "Neo Galaxy-Eyes Cipher Dragon". Kite took control of "Moon Protector" and Tributed it to bring back the original "Cipher Dragon" with "Galaxy-Eyes Nova". Diana panicked as both dragons attacked her directly, defeating her.
Diana uses a Deck centered on Fusion Summoning "Penumbral Keeper". Her strategy revolves around creating "Keeper Shield Tokens" through the effects of "Penumbral Keeper" and "Admiration of the Keepers", which prevents "Penumbral Keeper" from being destroyed. With "Admiration of the Keepers" she's capable of nullifying her opponent's ace monsters's effects while forcing them to attack the "Shield Tokens" or they risk getting that monster destroyed, in turn making the opponent's monsters substantially weaker while granting additional benefits for Diana.