This is how Celestia and Luna learn of Ekimu and Makuta goes in My Little Pony: Bionicle.
[Celestia levitates a book with her magic]
Princess Celestia: The Legend of the Bionicle.
Princess Luna: A thousand year old legend.
[The book flips through pages until it stops at the page with Okoto]
Narrator: A long time ago in the on the mythical island of Okoto, all lived in harmony. It was a place of wonders and beautiful landscapes.
[We see the vast city. We then see the island's elements, Jungle, Stone, Water, Fire, Ice, and Earth]
Narrator: From the island's elemental forces, two brothers, known as the Mask Makers, created Masks of Power.
[We see Makuta and Ekimu]
Narrator: Each brother had a special mask. Makuta owned the Mask of Control.
[We see the Mask of Control behind a purple background]
Narrator: And Ekimu the Mask of Creation.
[We see the Mask of Creation behind a blue background]
Narrator: The brothers provided the islanders with many masks, but Ekimu's were the most treasured.
[We see Ekimu with his most treasured masks]
Narrator: His brother became envious and forged an evil plan.
[We see Makuta growing jealous of his brother's success. The scene then shifts to Ekimu and Makuta shaking hands]
Narrator: It was a sacred law that a mask could never contain the power of more than one element. Otherwise it would become too strong and dangerous.
[We then see Makuta making the Mask of Ultimate Power]
Narrator: But Makuta wanted to create the strongest mask of all time.
[We see the Mask of Ultimate Power]
Narrator: The Mask of Ultimate Power.
[We see Makuta holding the Mask of Ultimate Power. When he puts it on, he becomes put under its influence and his gold parts turn black and his purple parts turn red]
Narrator: When Makuta put it on, it took control over him and the island began to shake and crumble.
[We see Ekimu looking shocked]
Narrator: Realizing what his brother had done, Ekimu managed to knock the mask from Makuta's face.
[Ekimu uses his hammer to knock the Mask from Makuta's face]
Narrator: A shockwave rolled across the land and sent both brothers into an endless sleep.
[A shockwave flies over the city and knocks Makuta and Ekimu out]
Narrator: The masks were scattered all over the island, waiting for a time when someone would come looking for them.
[The masks are shown on a golden background]
[The book closes]
Princess Celestia: These two brothers must be just like us.
Princess Luna: Back when I turned into Nightmare Moon, I was just like Makuta. Only I wasn't under the corrupting influence of a mask like he was.