|“||Do you truly believe our species can coexist?... Even after you saw what they did? No...I won't put our kingdom through that pain again. I'll follow the rules our king left for us. If you still desire to go against his rules...then... Fight me.||„|
|~ Agate Lightvale|
She had ignored the rules of magic and experimented with forbidden spells, such as inverting your soul trait, and the "Bête Noire" spell. It is said that inverted bravery soul is not the only requirement to perform the spell, but it is unknown what else was required for it, such as another body. Consequentially, the use of this forbidden magic caused her to experience a very slow and painful death.
Near the beginning of the episode, Betty's "mother" told Gaster that Bete needs to stay in Gaster's Lab. Bete's "mother" appeared to look very similar to Agate. But since Agate was dead at the time, it turned out that it was a hallucination by Bete.
Gaster then reads the story of "Human History: Volume 9" and gets the following information: "Sometime after the barrier was created, Copper and his sister Agate fought against each other to determine if the barrier should be destroyed or not. Thanks to his trait's great strength, Copper was victorious. As for Agate, losing the fight caused her to lose her trait. Out of humiliation, she ran away and went missing, being nowhere to be seen for a long amount of time.
Eventually, after inverting her trait, a very dangerous and forbidden spell on her soul, Agate returned for a rematch against her brother. This time, however, she managed to kill him, and the kingdom fell in ruin due to the fact that there was no one to rule. Unfortunately for her, Agate's soul was unable to adapt to the change due to the result of the spell she cast upon it. Therefore, she sacrificed her very own soul to create the most powerful and destructive being imaginable, who would ensure that humans and monsters would never live in peace with one another.
This episode managed to provide more detail on Agate and Copper, and the episode began, we can witness that Amber was born during the night. Copper and Agate were watching the scene and just saw what could most likely be their mother dying. Her soul, which is presumably an Integrity soul, cracked and eventually shattered upon Amber's birth.
However, things began to change once the two siblings started to argue over whether the barrier should be kept or not. This eventually led to them battling, with Copper winning due to his determination soul's strength. Agate's loss humiliated her, causing her to lose her trait, and flee the kingdom. She started looking for a trait that had a chance to defeat DETERMINATION, and in doing so, she found it: FEAR.
Later, Copper and Agate were reunited, though something seemed different about Agate this time, so once again, she challenged her brother. However, it was against his will. This time though, she ended up winning because, during the fight, Agate had killed Amber, causing Copper to lose his trait out of fear. She then proceeded to kill him whilst he was frozen on his knees, shocked over what he was witnessing. Knowing that her time was running short because her soul was cracking, she performed the Bête Noire spell in a cave and used Amber as a vessel for it.
Agate only made a (non-physical) cameo in this episode. She popped up when Asgore said that Bete was the result of "a twisted mind's spell."
At the stadium, while King Asgore and Toriel are battling against Bete, Toriel attacks Bete with her fire magic, one of her strong strikes. Just after that, King Asgore and Toriel make a combined attack at Betty; however, Bete easily blocks the attack, reflects it, and then shoots it back towards them.
Here, at the moment, Agate makes another non-physical cameo; here, she appears behind Bete as she returns the flames that Toriel and Asgore fired together, signifying that Asgore realized who Bete truly was.
Powers and Abilities
- Spear of Bravery: Agate could use her spear to deals serious damage to her opponents, the damage is enough to kill them.
- Magic Blasts: Agate possessed the ability to create powerful blasts capable of destroying anything in her way.
- Dark Magic: Agate is known in Human History for experimenting with forbidden spells such as inverting her trait to grow stronger.
- Inflicting FEAR: It is most likely that Agate can inflict fear to others after she inverted her soul trait, this is based on Human History Chapter 26.
- Bete Noire spell: Agate performs a spell the requires an inverted soul and a body to create (summon) a creature that is neither human nor monster.
Agate wore an orange long-sleeved t-shirt, a light orange skirt that covers most of her legs, and an orange bow on her back that sometimes appears yellow. She had very wavy and long orange hair that became dark orange after inverting her trait and pink after gaining a soul of FEAR.
|“||Actually, Agate was a rather nice person, she was however emotionally weak, she was very emotional over everything and it was easy to hurt her that way. When she lost the battle against her brother in front of so many people having the little confidence she had in herself destroyed upon losing, it destroyed her internally so she ran away and made poor life choices. When she inverted her trait her whole personality changed and nothing was left of her past self, she became insane and… well did what we all know she did. If I’m being perfectly honest Copper should’ve known better, knowing his sister’s personality he should’ve seen that maybe losing the battle would take a much bigger toll on her than what it could do to him, especially under the circumstances that happened. She literally lost her trait due to losing and he didn’t immediately go after her to try to fix things, the heat of the battle didn’t let him react in time. It was the perfect storm.||„|
|~ Camila Cuevas|
Originally, Agate was a kind and selfless young woman that greatly valued her family and seemed to act like a motherly figure around Amber. However, it was no secret that Agate believed that the barrier should be kept up. Though, this wasn't because she hated monsters but rather because she believed that humans and monsters living together would cause more wars, meaning that she was simply trying to keep the peace. She also might've been bold and confident, as shown when she bravely challenged Copper. But it comes to a surprise, that she was not mentally brave, and she always followed what her superiors had to say, showing that she was also submissive.
Unfortunately, everything changed after she lost her battle with her twin brother Copper Lightvale. This brought unbearable humiliation upon her, causing her to lose her trait, and run away. In fact, she became obsessed with ensuring humans and monsters never live with each other and began to seek revenge on Copper for humiliating her. In fact, she was willing to go great lengths, such as committing murder in order to achieve these goals.
After inverting her trait, she turned completely insane, immensely violent, horrifyingly ruthless, and highly sadistic, always smiling psychotically in the face of her opponent's pain. She clearly didn't care about the people she hurt (even if they were children) and showed no problem with corrupting innocent people. A perfect example of her cruelty was when she smiled and showed no remorse when she forced Copper to watch her kill her own sister, Amber Lightvale, who was completely defenseless and innocent; she did nothing but act as a loving younger sister to both Agate and Copper. All Amber wanted was to be a good and loving sister, but due to the cruelty that humanity contained, Agate, the true monster, murdered both Amber and Copper in cold blood.
Even after all she did, Agate seemed to have believed that she was a good person and failed to see the wrong in her evil deeds, but it is obvious that she is far from sympathetic the moment she willingly embraced evil.
Agate used to have redeeming qualities but lost them out of her quest for revenge because she used HATE to do so, which caused her to completely lose any redeeming qualities she may still possess before.
- Agate was very good friends with Rin.
- Bete Noire knows what happened in the past, because Bete Noire has all the memories of her "creator" (Agate), due to having her creator's soul.
- It is unknown if the story of Copper, Agate, and Amber Lightvale would change if hard mode weren't activated, as this is because a lot of things changed once Frisk went into Hard mode.
- Agate's name probably originated from Agateophobia, which is the fear of insanity.
- Inverting your soul trait will give you a high chance of your painful death. (Example: Agate Lightvale died when she inverted her soul trait to FEAR.)
- Agate Lightvale and Copper Lightvale came from the beginning of Undertale.
- Copper and Agate could also be named after the minerals, Copper, and Agate.
- Also, there's another mineral named Copper Agate.
- Amber can also mean a fossilized resin, which usually preserves things, just like how Amber's body preserved Agate's soul.
- Agate and Copper's father most likely died a few years before the war times.
- Agate, even when dead, is still responsible for the creation of Bete, and it is still her fault (Frisk could still be blamed) for creating the conflict in Season 2 since Bete Noire was created to fix the glitches.
- Even though Agate had a Bravery soul, she lost her trait after getting defeated by Copper, which could mean she had Kakorrhaphiophobia, or Atychiphobia, which means the fear of defeat.
- If Agate used Copper as the vessel for the Bete Noire spell, the spell would've been stronger than the currently known Bete Noire, but she didn't because of her massive hatred and bitterness towards Copper.
- There was a ten-year-long gap between the creation of the barrier and Agate and Copper's incident.
- Agate possessed physical bravery, while her emotional/moral bravery was almost non-existent. This made her extremely emotionally unstable according to a post from Camila Cuevas.
- Before Agate and Copper fought, Agate was jealous of Copper due to the fact that he possessed a Determination soul, a trait that she knew she couldn't overpower.
- Agate Lightvale is technically Bete Noire in a way because her soul was the one used to make the spell.
- Agate and Copper killed the most monsters during the war out of all seven wizards. 
- Copper and Agate were in charge of a small city in the middle of the continent. As seen in this picture. 
- As of Hate, Asgore knows Bete is Agate. It is possible Gaster knows too, as he had read the book on the twins.
- When Agate and Copper were children, Copper would always manage to get himself hurt despite Agate's warnings beforehand. As teenagers, these roles switched with Agate becoming the more rash one.
- ↑ https://camilaart.tumblr.com/post/183631625665/so-if-copper-stayed-clumsy-would-he-have-been-the
- ↑ http://camilaart.tumblr.com/post/167638454210/does-bete-remember-at-least-something-about-her
- ↑ http://camilaart.tumblr.com/post/165215064835/saw-an-okd-ask-on-the-fact-that-you-can-invert
- ↑ http://camilaart.tumblr.com/post/164311505715/joshy29-camilaart-clever-very-clever
- ↑ http://camilaart.tumblr.com/post/167813379615/what-happened-to-agates-ambers-and-coppers
- ↑ http://camilaart.tumblr.com/post/168898656575/im-thinking-if-agat-used-not-ambers-body-for
- ↑ http://camilaart.tumblr.com/post/172220122900/i-just-realized-something-gaster-and-asgore-knew
- ↑ http://camilaart.tumblr.com/post/172632756100/when-agate-got-defeated-by-copper-she-lost-her#notes
- ↑ http://camilaart.tumblr.com/post/175456007655/im-guessing-agate-was-jelous-of-copper-when-she
- ↑ http://camilaart.tumblr.com/post/176172915595/is-agate-controlling-betty-come-to-think-of-it
- ↑ http://camilaart.tumblr.com/post/183620731800/i-want-to-know-random-facts-about-copper-lightvale
|Villains||HATE ♡ Chara ♡ Agate Lightvale ♡ Bête Noire ♡|
|Main Characters||Frisk ♡ Gaster ♡ Sans ♡ Flowey ♡/Asriel ♡ Undyne ♡ Papyrus ♡ Toriel ♡ Asgore ♡ Alphys ♡ Mettaton ♡|
|Side Characters||Jessica Grey ♡ Ellie Winterway ♡ Amber Lightvale ♡ Cam ♡ Lily ♡ Robin ♡ Abigail ♡ Seth ♡ Zachary ♡ Hugo ♡ Ronan Cass ♡ Rave Rutrow ♡ Isabelle ♡ Miasma ♡ Jessee Krovor ♡ Amai Yuki ♡ Kanashi Fukitsu ♡ Kennari ♡ Grace Rutrow ♡ Adrian Garza ♡ Milo ♡ Kauzku Triuzar ♡|
|Background Characters||Temmie ♡ Burgerpants ♡ Jerry ♡ Grillby ♡ Muffet ♡ Amalgamates ♡ Alina ♡ Noah Rutrow ♡ Akumu/Pink Creature(s)/Kumuzilla ♡ Zoe Phenix ♡ Jun Youmei ♡|
|The Seven Wizards||Copper Lightvale ♡ Agate Lightvale ♡ Roy Goldburn ♡ Shane Goldburn ♡ Mila Rutrow ♡ Kody Fallenfire ♡ Rin Winterway ♡|