Cursed art from a Cursed Cat

Though the brothers buried the corpse, the torn earth told the truth. Quite literally, in fact: when Lugh arrived at the site, the earth spoke, recounting what happened. As punishment, Lugh places an eric—a toll for taking a life—on the brothers: they are tasked with traversing the world and collecting eight treasures. These consisted of three apples from the Garden of the Hesperides (of Greek myth); a pigskin capable of perfectly healing anyone from King Tuis of Greece; a poison-tipped spear (debated as to being the Gáe Assail or the Areadbhair) from King Pisear of Persia; two horses and a chariot that can ride across the ocean from King Dobar of Sicily; seven pigs that can be eaten and reappear in the morning from King Easal of the Golden Pillars; the young pup Failinis from the King of loruaidh; the cooking spit of the women of Inis Fionnchuire, an underwater island lying between Ireland and Britain; and three shouts from atop the hill of Miodhchaoin. The brothers were able to accomplish the first seven tasks. These typically followed a pattern of Brian deciding to appear in the court of the given king as a poet or mercenary seeking work, directly asking the king to just give them what they want, and slaughtering everyone when they are denied. However, the last task would be the end of them: Miodhchaoin and his three sons would do battle with the brothers, already left ragged from their previous encounters. Though Brain, Iucha[i]r and Iucharba came out victorious, they would live just long enough to shout thrice from the hilltop.

The most apparent connection between the sons of Tuireann and the sons of Danann is found in the characters' personalities. In Genealogy of the Holy War, Brian seeks vengeance for the death of his father and grandfather and remains allied to Julius and the Loptrian Empire. Iuchar and Iucharba are both conditioned by their father to enact injustices upon the people of Isaach, but in truth have good intentions. Iuchar in particular leans more into the comedic aspect the younger Tuireann brothers present in the Irish tale.

In Japanese, Brian's name is ブリアン (rōmaji: burian), and is officially romanized as Burian. Far less obvious are the names of the younger brothers; in Japanese, Iuchar is named ヨハン (rōmaji: yohan), officially romanized as Johan, while Iucharba is named ヨハルヴァ (rōmaji: yoharuva), officially romanized as Johalva. As it turns out, the similar ヨハル (rōmaji: yoharu) and identical ヨハルヴァ are some of the most common renderings of Iuchar and Iucharba, though ユッハル (rōmaji: yuhharu)and ユッハルヴァ (rōmaji: yuhharuva) are also frequently used.

Though not named after their father, Danann's name is also very deliberate both in Japanese and internationally. Danann comes from the Tuatha Dé Danann, the group of deities to which Dagda, Lugh, and Tuireann's family belong. The name of the Tuatha Dé Danann means "People of the goddess Danu"; the identity is a controversial subject, as the name doesn't appear much beyond this. However, in the Lebor Gabála Érenn, amongst the genealogies of the Tuath Dé, it is mentioned that Brian, Iuchar, and Iucharba—listed instead as three of six sons of Delbáeth, also called Tuirell Bicreo—were born of Delbáeth's own daughter, Donann (sometimes called Danand). For this, they are called the "three gods of Danu". In Japanese, Danann is named ダナン (rōmaji: danan), officially romanized as Danan. This name most likely is based on the same information.

The city of Dahna also relates to the Tuatha Dé Danann; at least, with its Japanese name. In the original language, Dahna is called ダーナ (rōmaji: dāna), officially romanized as Darna. This is derived from ダーナ神族 (rōmaji: dāna shinzoku), translating to "Dan[u] god tribe", a less common rendering of the Tuatha Dé Danann in Japanese based on the literal meaning. As the city is the site the modern gods of Jugdral blessed the Twelve Crusaders—who in themselves have been deified over the hundred years since their time—it makes sense for this location to carry the name of the Tuath Dé. This name choice also relates to the Second Battle of Mag Tuired, in which the Tuath Dé, long oppressed by the Fomorians that ruled Ireland after their arrival, revolt and return to power—much like the people of Jugdral did to the Loptrians.