Spoilers for the Medal Queen's true identity below
The mysterious Medal Queen, who could she really be? Why does she look like the Grand Noah Queen? A long lost, twin sister?
Grand Noah Queen is potentially first met at the Medal Queen's Castle where she trades some amazing items for the small medals you've been finding scattered about. If you trade 45 small medals, you can recruit the Medal Queen, and the interface will reveal that she is secretly the Queen of Grand Noah.
She plays a major role in Part 2, but you cannot gain an audience with her until you've recruited Sara as a companion. Luka and Sara gains an audience to the Grand Noah Queen under conditions that Luka should participate on the Queen's Cup on the Colloseum by Mephisto. The Grand Noah Queen accepts the condition to prove that Luka can be trusted. Luka later manages to win the tournament only to find out that this tournament was set up by Mephisto to bait Alma Elma as she appeared in the correct timeline. As a reward for second place, she grants Luka the Green Orb.
Afterward, she asks Luka to investigate Mephisto's Magic Academy to find out evidence of Mephisto's treachery. When the latter's game are exposed to light, the Grand Noah queen asks her to resume her operation as an advisor.
She later assists Luka in infiltrating Gold Fort. When the war is over, she participates in a banquet with the other human lors before being interrupted by a declaration of war from Alice XV. When it is clear that the Monster Lord won't immediately attack, she asks Luka to go help Grangold with their local troubles.
The Grand Noah queen reappears when the Monster Lord's forces finally attack, and with the support of her fellow lords, come with a plan to counter-attack and cripple them.
She also plays a role in "The Land of Night and the Heroes of the Seven Worlds". She leaves the Pocket Castle to use her authority as the Grand Noah queen to support Luka in his investigation. However, she gets brainwashed by Musette, and imprisons Lest. She claims that she already knows that they were going to Grand Noah all along and Lest and Tarsa unknowingly sprung a trap created by the Yoma. She's freed from her brainwashing a bit later, for unclear reasons. When the meeting to prepare the assault on the Château des Romances happens, she tells that she can't send her army against the Nightmares as they would be useless, and the heroine agrees that even Battle Fuckers would be not enough.
She is seen again during the post collab as she tasks the party with finding Musette, Bell and Lyla. Upon discussing with Mephisto, the duo suggests checking on Snow Heaven. When the party finall take down the troublemakers, she asks Luka to take them into their custody as Grand Noah doesn't possess the infrastructure or the guards able to resist their brainwashing abilities.
You can trade medals with her at the Medal Queen's Castle.
Queen of Grand Noah: “Ahh, what beautiful medals...”
Lime: “Your majestyyyy! I found a small medaaal!”
Queen of Grand Noah: “Let's see... Oh, this isn't a medal. Is this a bottle cap?”
Lime: “Whaaat...? That's disappointing...”
Queen of Grand Noah: “...But I also collect bottle caps. How about I trade you for a cookie?”
Lime: “Yaay! Thank youuu!”
Sonya: “That's awfully kind of you, your majesty.”
Queen of Grand Noah: “Oh, it's actually very interesting in it's own way. It's 64 years old, and was made in the Delia Workshop...”
Sonya: “(She actually collects bottle caps?)”
Miranda: “Wait, isn't she Grand Noah's...?! I wonder how much I could squeeze out of her if I kidnapped her here...”
Queen of Grand Noah: “Unfortunately, I am just a mysterious medal queen. You won't be able to ransom me.”
Miranda: “What? You're not her? Sorry about that.”
Sonya: “(She was tricked that easily?!)”
Arthur: “Your Majesty... This sword shall always be used for your sake!”
Queen of Grand Noah: “No, I am the queen of unidentified medals...”
Arthur: “M-my apologies...”
Queen of Grand Noah: “Your queen would consider your loyalty to be reassuring. Please continue to fight for your country in the future.”
Arthur: “Ha! With pleasure!”
Caesar: “My strength is for the sake of Your Majesty!”
Queen of Grand Noah: “No, I am the queen of unidentified medals...”
Caesar: “How rude of me...”
Queen of Grand Noah: “No way, did she really not notice...?”
Mephisto: “Your Majesty... Why have you trusted me thus far? Have you not considered the possibility I could betray you at the last minute?”
Queen of Grand Noah: “I do not trust you, but I do depend on you. Does your pride not permit you to betray me?”
Mephisto: “I see, you have a very good eye for people. Do you respect me based on my sense of values rather than trust?”
Queen of Grand Noah: “I believe you... Is that what you wanted me to say?”
Mephisto: “Yes, of course...”
Sonya: “Umm, is this really okay? You're out on an adventure even though you're a queen...”
Queen of Grand Noah: “Meda-- ...Ensuring the safety of the world is part of a ruler's duties. To that end, it is appropriate for me to be willing to go on a long journey.”
Sonya: “(...She almost said 'medals.')”
Sara: “The Queen of Grand Noah. Long time no see.”
Queen of Grand Noah: “Oh my, who have you mistaken me for? I am just a mysterious medal queen.”
Sara: “You're that determined to keep up your persona?”
With Grangold King:
King of Grangold: “Queen of Grand Noah... Although we are fellow cousins, it has been a very long time. You seem to have changed since I last saw you at the banquet about a decade ago.”
Queen of Grand Noah: “At that time, I had yet to ascend to the throne. You have changed a lot...or rather, you have transformed.”
King of Grangold: “Your Majesty, why don't you consider transforming a few stages further?”
Queen of Grand Noah: “No... I shall refrain.”
Queen of Grand Noah: “Ahh, medals are so beautiful. I could look at them for hours and never get tired.”
Queen of Grand Noah carefully polishes a medal with a small piece of cloth.
Queen of Grand Noah: “Even a noble such as myself possesses some level of musical talent.”
Queen of Grand Noah played the violin...
Not bad, but not everyone was listening.
Queen of Grand Noah: “All my subjects! Grovel at my feet!”
Queen of Grand Noah is practicing her catchphrase...
Queen of Grand Noah: “You there, obey my command...”
Queen of Grand Noah sends a flirtatious glance at [Enemy]!
[Chance to seduce random enemy]
Queen of Grand Noah: “Excuse me, I must attend to a daily ritual...”
Queen of Grand Noah stuffs hair from the King of Grangold into a straw doll.
She then nails it to a tree with a long spike!
- If you try and meet the Grand Noah Queen while the Medal Queen is in your party, she'll excuse herself for a moment and leave the party before you can enter the throne room.
- She is the third ruler of the 4 major powers that were brainwashed by a monster.