Leo's twin sister is also one of the Signers. Completely opposite to Leo, Luna is gentle, polite, and mature for her age. She has the ability to hear the voices of Duel Monsters spirits, so she builds her FairyDeck using those same monsters. Her ace monster is not only a Signer Dragon, but also her friend: "Ancient Fairy Dragon".
When starting a Duel with Yusei Fudo, Jack Atlas, or Crow Hogan, Luna says "I'm Team 5D's too! I'll prove I can hold my own!"
When she wins the Duel, she says "These techniques weren't my own.", followed by "I learned them from you! And from all my friends!"
When she loses the Duel, she says "I'm not worried. With your help, I can get stronger!"
Akiza Izinski
When starting a Duel with Akiza Izinski, Luna says "Akiza, can you teach my some new techniques to baffle Leo?"
When she wins the Duel, she says "Hooray! I finally defeated Akiza!"
When she loses the Duel, she says "That's why you're the best student at the Academy, Akiza.", followed by "I have a lot to work on if I want to reach your level."
Leo
When starting a Duel with Leo, Leo says "Leo, you actually have some cool moves to show me?"
When she wins the Duel, she says "Sheesh, you need to try harder. Or you'll never be #1!"
When she loses the Duel, she says "Leo, you've changed. You're more... mature.", followed by "Like you're an ACTUAL big brother!"
Dark Signer Kalin Kessler, Dark Signer Carly Carmine, Dark Signer Rex Goodwin, Earthbound Immortal Ccarayhua, Earthbound Immortal Chacu Challhua, Earthbound Immortal Cusillu, Earthbound Immortal Uru
Before Luna Synchro Summons "Ancient Fairy Dragon", she announces "The magic that lives in each creature merge and become one!", followed by "Synchro Summon!" When Luna Summons "Ancient Fairy Dragon" (by any method), a cut-in frame of Luna briefly appears, and she announces "The mighty, the majestic... Ancient Fairy Dragon!" If its Summoning animation has not already played this Duel, a cutscene of "Ancient Fairy Dragon" being Summoned plays afterwards.
Most of the time when Luna attacks with that monster, she announces "Ancient Fairy Dragon! Attack!", followed by "Eternal Sunshine!"
When Luna activates that monster's effect, she announces "Ancient Fairy Dragon's effect activates!"
When she chooses that monster's first effect, she announces "I Special Summon a Level 4 or lower monster from my hand!"
When she chooses that monster's second effect, she announces "Plain Back!"
Before Luna Synchro Summons "Ancient Pixie Dragon", she announces "The spirit of the ancient fores takes solid form!", followed by "Synchro Summon!" When Luna Summons "Ancient Pixie Dragon" (by any method), a cut-in frame of Luna briefly appears, and she announces "Ancient Pixie Dragon!"
Most of the time when Luna attacks with that monster, she announces "Go, Ancient Pixie Dragon!", followed by "Fairy Tail Whip!"
When Luna activates that monster's Trigger Effect, she announces "Ancient Pixie Dragon's effect activates!", followed by "When a Field Spell activates on my turn, I draw a card!"
When Luna activates that monster's Ignition Effect, she announces "Since there's a Field in play... Go, Ancient Pixie Dragon!", followed by "Destroy a monster in face-up Attack Position!", followed by "Spirit Burial!"
When Luna Summons "Kuribon", a cut-in frame of Luna's face briefly appears, and she announces "I need you, Kuribon!"
Most of the time when Luna attacks with that monster, she announces "Go, Kuribon! Attack!"
When Luna activates that monster's effect, she announces "Kuribon! Use your effect!"
Before Luna Synchro Summons "Power Tool Dragon", she announces "Machine and might combine to bring peace to the world!", followed by "Synchro Summon!" When Luna Summons "Power Tool Dragon" (by any method), a cut-in frame of Luna's face briefly appears, and she announces "I know you can win, Power Tool Dragon!"
Most of the time when Luna attacks with that monster, she announces "Attack, Power Tool Dragon!", followed by "Crafty Break!"
When Luna activates that monster's effect, she announces "Power Tool Dragon adds an Equip Spell to my hand!", followed by "Power Search!"
Before Luna Synchro Summons "Power Tool Mecha Dragon", she announces "If you wanna feel the steel, be my guest!", followed by "Synchro Summon!" When Luna Summons "Power Tool Mecha Dragon" (by any method), a cut-in frame of Luna's face briefly appears, and she announces "Power Tool Mecha Dragon!"
Most of the time when Luna attacks with that monster, she announces "Attack, Power Tool Mecha Dragon!", followed by "Full Metal Demolition!"
When Luna activates that monster's Trigger Effect, she announces "Power Tool Mecha Dragon's drawing effect activates!", followed by "Equip Bonus!"
When Luna activates that monster's Quick Effect, she announces "Power Tool Mecha Dragon's effect activates!", followed by "Equip Grappling!"
When Luna Summons "Sunlight Unicorn", a cut-in frame of Luna's face briefly appears, and she announces "Sunlight Unicorn! Appear!"
Most of the time when Luna attacks with that monster, she announces "My Sunlight Unicorn attacks!"
When Luna activates that monster's effect, she announces "Sunlight Unicorn's effect activates!", "If my deck's top card is an Equip Spell, I get to have it!"
When Luna Summons "Ancient Elf", she announces "Here comes Ancient Elf!"
Most of the time when Luna attacks with that monster, she announces "Ancient Elf attacks!"
When Luna Summons "Armored White Bear", she announces "Armored White Bear!"
Most of the time when Luna attacks with that monster, she announces "Armored White Bear! Charge!"
When Luna activates that monster's effect, she announces "Armored White Bear's effect activates!"
When Luna Summons "Bird of Roses", she announces "Fly, Bird of Roses!"
Most of the time when Luna attacks with that monster, she announces "Bird of Roses attacks!"
When Luna activates that monster's effect, she announces "Bird of Roses activates its effect!"
When Luna Summons "Dancing Fairy", she announces "Let's fight together, Dancing Fairy!"
Most of the time when Luna attacks with that monster, she announces "Dancing Fairy! Dance all over 'em!"
When Luna activates that monster's effect, she announces "Dancing Fairy's effect activates!", followed by "1000 Life Points are coming back to me!"
When Luna Summons "Dark Sage", she announces "I Special Summon Dark Sage!", followed by "Whoa! You said you were old, but I didn't think THAT old!"
Most of the time when Luna attacks with that monster, she announces "Dark Sage! Attack!"
When Luna activates either of that monster's effects, she announces "Dark Sage's effect activates!"
When Luna Summons "Dreamsprite", she announces "Dreamsprite!"
Most of the time when Luna attacks with that monster, she announces "Attack, my Dreamsprite!"
When Luna activates that monster's effect, she announces "Dreamsprite's effect activates!"
When Luna Summons "Fairy Archer", she announces "Please aid me, Fairy Archer!"
Most of the time when Luna attacks with that monster, she announces "Fairy Archer! Fire!"
When Luna activates that monster's effect, she announces "Fairy Archer's effect activates!"
When Luna Summons "Fairy King Truesdale", she announces "Fairy King Truesdale arrives to protect my spirits!"
Most of the time when Luna attacks with that monster, she announces "Fairy King Truesdale attacks!"
When Luna Summons "Fairy's Gift", she announces "Fairy's Gift!"
Most of the time when Luna attacks with that monster, she announces "Fairy's Gift! Attack!", followed by "Enchanted Dust!"
When Luna Summons "Jerry Beans Man", she announces "I know you'll fight for me, Jerry Beans Man!"
Most of the time when Luna attacks with that monster, she announces "Slash 'em with your sword, Jerry Beans Man!"
When Luna Summons "Key Mace", she announces "It's okay. Come on out, Key Mace."
Most of the time when Luna attacks with that monster, she announces "Key Mace attacks!"
When Luna Summons "Nettles", she announces "The Tuner Monster, Nettles!"
Most of the time when Luna attacks with that monster, she announces "Nettles! Attack!"
When Luna Summons "Petit Angel", she announces "Join me, Petit Angel!"
Most of the time when Luna attacks with that monster, she announces "Attack, Petit Angel!"
When Luna Summons "Regulus", she announces "Lend me your strength, Regulus!"
Most of the time when Luna attacks with that monster, she announces "Regulus! Pounce!"
When Luna activates that monster's effect, she announces "Regulus's effect activates!", followed by "I return a Field Spell in my Graveyard to my deck!"
When Luna Summons "Spirit of the Breeze", she announces "Come to me! Spirit of the Breeze!"
Most of the time when Luna attacks with that monster, she announces "Spirit of the Breeze attacks!"
When Luna activates that monster's effect, she announces "Here's Spirit of the Breeze's effect!", followed by "I regain 1000 Life Points!"
When Luna Summons "Spore", she announces "The Tuner Monster, Spore!"
Most of the time when Luna attacks with that monster, she announces "Spore! Attack!"
When Luna activates that monster's effect, she announces "Spore's effect activates from the Graveyard!"
When Luna Summons "Sunny Pixie", she announces "The Tuner Monster, Sunny Pixie!"
Most of the time when Luna attacks with that monster, she announces "Attack, Sunny Pixie!"
When Luna activates that monster's effect, she announces "Sunny Pixie uses her effect!", followed by "I gain 1000 Life Points!"
When Luna Summons "Watapon", she announces "Let's go, Watapon!"
Most of the time when Luna attacks with that monster, she announces "Watapon! Attack!"
When Luna activates that monster's effect, she announces "If an effect adds Watapon to my hand, I can summon it!"
Spells/Traps
When Luna activates "Ancient Forest", she announces "I activate the Field Spell, Ancient Forest!"
When Luna activates that card's effect, she announces "Ancient Forest's effect!", followed by "Monsters aren't allowed to fight among these trees!"
When Luna activates "Central Shield", she announces "Leo is always with me, along with his shield!", followed by "The Equip Spell, Central Shield!"
When Luna activates "Double Ripple", she announces "I'll activate the Spell Card, Double Ripple!", followed by "Help me, Ancient Fairy Dragon and Power Tool Dragon!"
When Luna activates "Fairy Wind", she announces "I flip over my Trap Card! Fairy Wind!"
When Luna activates "Horn of the Unicorn", she announces "I equip the Equip Spell, Horn of the Unicorn!"
When Luna activates that card's effect, she announces "Horn of the Unicorn returns to the top of my deck."
When Luna activates "Pain to Power", she announces "I equip the Equip Spell, Pain to Power!"
When Luna activates that card's effect, she announces "I'll change these stings into strength!", followed by "Pain to Power's effect activates!"
When Luna activates "Pixie Ring" or its effect, she announces "I reveal my Continuous Trap! Pixie Ring!"
When Luna activates "Rocket Pilder" or its effect, she announces "The Equip Spell, Rocket Pilder!"
When Luna activates "Solemn Wishes" or its effect, she announces "I activate the Continuous Trap, Solemn Wishes!"