Colosso is an annual festival held in Tolbi arranged by its lord Babi. This festival is world famous to a degree because of its scope, and central to it is a prestigious tournament of warriors that is often what the name "Colosso" is used to refer to. The Colosso tournament is the premier tournament of warriors across Weyard and is where all warriors dream of proving their valor.
Tolbi has become Weyard's most metropolitan city because of its hosting the Colosso festival once a year, with its tournament being the premier event for warriors across Weyard to compete in, and the overall festival is the biggest hot spot for tourism in the world. It was conceived and established by the lord of Tolbi, Babi, for personal reasons not known to the public. The festival includes many things set up as attractions, such as the Lucky Medal game at Tolbi Spring and the casino-like Lucky Dice. But the event that has become synonymous with the name "Colosso" is the tournament of warriors that takes place in huge stadiums physically connected to Babi's Palace, and these stadiums are accessible by either walking into the main Colosseum Entrance or by travelling through the Colosseum Tunnel to reach the bleachers. Babi himself, along with his chief minister Iodem, uses this tunnel to come to the throne at the head of the stadium to look upon the competition.
In the Colosso competitions, warriors compete in displays of strength and cunning. In the Colosso Trials (also called the Colosso Preliminaries), the many entrants to the current year's Colosso are filtered by qualification trials that measure aspects of each warrior's abilities, such as physical strength in a weight lifting competition, and seven finalists are selected as Colosso Gladiators to proceed to the Colosso Finals, which is a series of races whose stage layouts test both physical ability and momentary cunning. Each year, the gladiators strong enough to win or come close to the championship are offered positions as soldiers and bodyguards in Babi's Palace; indeed, the solders seen under Babi's employ in Golden Sun are champions of prior Colosso events, or at least have placed high enough to receive Babi's approval. And even if warriors do not actually achieve the ultimate goal in Colosso, their participation in Colosso is beneficial because demonstrating their strength to the public in this fashion increases their reputation, which helps them contract jobs as mercenaries and other things for clients.
Colosso's tournament itself is also a pure spectator's event. The trials alone take place in a giant stadium whose bleachers are inevitably filled up, and each of the finals matches take place in specialized arenas that end up filled with spectators on the sidelines. Since the event is so major, even scalping is made a business among the people, where people buy seats in advance and sell seats to spectators at increased prices. Residents of Tolbi also get to play a lottery-style game called Lucky Guess during each year's Colosso where they bet on which of the Colosso gladiators will win the championship, similar to real-world horse racing betting.
- Main article: Colosso Finals
The Colosso Final Competitions takes place after the Colosso trials and is the effective main event of the entire festival. The Finals are comprised of three series of stages that have simple puzzles integrated into their layout, and the seven highest ranked Colosso Gladiators from the Colosso trials face off in these series of puzzle-like races where they eventually meet in a central arena and engage in one-on-one duels. This is a major gameplay episode in Golden Sun that occurs after completing Altmiller Cave, and when Isaac competes in them he must win at least the first two matches.
Babi is over 150 years old. This did not occur naturally; Babi had long ago been caught up in the Great Flood and ended up in the mythical island society of Lemuria, whose Mercury Adept inhabitants live for centuries thanks to an Alchemy-based influence that pervades the city, and they had a stockpile of Lemurian Draught which allows an outsider who drinks it routinely to live beyond his normal years even outside Lemuria. Babi ended up fleeing the isle with a stolen Lemurian Ship and the whole stockpile of draught. His draught would allow him to live long enough to rule the city of Tolbi in Gondowan for over one hundred years, during which he presumably created the annual Colosso festival, which helped make him and his city among the most powerful in Weyard.
Babi cemented Colosso's worldwide popularity with its central event, a large-scale and prestigious tournament of warriors. Babi would realize in his later years, however, that his stockpile of life-preserving draught, which he kept in a magical vault in the depths of Altmiller Cave, wouldn't last forever. He figured the only way for him to keep on living is to go back to Lemuria and fetch another stockpile of draught for him. Lemuria, however, is effectively impossible to enter by conventional sailing methods because its area of the ocean, the Sea of Time, is surrounded by whirlpools and stone crags that would easily destroy wooden ships that try to sail through there. And even if the ship would survive, there are currents that would change a boat's direction subtly but tangibly enough that they would prevent would-be sailors from keeping a straight course on their ships. So, Babi sought one remedy for each of these two problems.
The first remedy was to order the construction of a giant watchtower named Babi Lighthouse on the easternmost point of Gondowan, the point on Gondowan closest to the foggy Sea of Time, so that its light could shine bright enough that sailors sailing into Lemuria will be able to keep their bearings. The other remedy was what Babi hoped to achieve by hosting Colosso itself: Find capable warriors who exhibited the same Psynergy powers as the Lemurians he encountered in Lemuria. Only Adepts can commandeer the Lemurian ship he stole because it runs on Psynergy power, and only a Lemurian Ship is sturdy and reliable enough to safely make its way through the Sea of Time into Lemuria. (Note that Babi had learned a little Psynergy during his stay in Lemuria, which allowed him to commandeer the Lemurian Ship far in the past.) By the time Golden Sun takes place which is during this year's Colosso season, Babi Lighthouse is close to completion, and Babi's draught stockpile has been nearly entirely consumed.
As this year's Colosso Trials start, Babi heads off into Altmiller Cave to fetch the last of his draught, but since he has been attempting to ration his drinks to extend his lifespan, he is weaker than normal and eventually collapses in the cave, but then fate intervenes and Isaac's traveling group of Adepts happens upon him while exploring the cave. They rescue him from an eventual death using their Psynergy powers to retrieve for him his last draught, which rejuvenates him. Grateful, Babi sees Isaac as the possible miracle warrior he desired to pilot his Lemurian Ship for him, and he decides to enter Isaac into the Colosso Finals so that he may observe the full extent of Isaac's Psynergy powers in battle.
At this point, Colosso has been lasting longer than it usually does, due to Babi's absence, but now he is back in his throne at Colosso and the finals begin in earnest. Nomally, seven warriors compete as the finalists as Colosso Gladiators, but for the first time in Colosso history an eighth warrior is entered personally by Babi himself, which is Isaac, to the mixed reactions of the spectators at Colosso. In the event, Isaac performs startlingly well in the eyes of the spectators, but Babi and his chief minister Iodem know that it is his Psynergy-enhanced battle abilities that is the real miracle at play. The third match is especially tough, and whether Isaac wins or loses the battle he will collapse from exhaustion on the arena afterward and actually go to sleep right away. In the event Isaac wins the battle, Babi and Iodem find it most rewarding to see Babi's favored warrior steal the day, and they present to Isaac afterward Colosso's victor's prize, the Lure Cap. Isaac will also gain some fame as a warrior that will influence later events in Golden Sun: The Lost Age.
With this year's Colosso now concluded, Babi explains to Isaac what he wants for him to do: With Iodem accompanying Isaac's group, they are to head to where Babi keeps his Lemurian Ship secretly ported, in the town of Lalivero near Babi Lighthouse and Venus Lighthouse, and make an attempt to reach Lemuria so that they may retrieve more Lemurian Draught for him. Isaac and company set out on their newly multi-layered quest, but in Golden Sun: The Lost Age they are ultimately unable to enter Lemuria, and Babi passes away from old age deprived of life-preserving draught. It is unknown what happens to the Colosso festival afterwards, though it is generally assumed that the festival and tournaments continue on each year as it is assumed Iodem takes Babi's place.
In The Lost Age
If Isaac won the Colosso tournament he participates in, and the player transfers their data from Golden Sun to The Lost Age, the three Colosso Gladiators that he defeats in battle, Azart, Satrage, and Navampa, will come together and conclude that Isaac's match must have been rigged, and they will decide to seek Isaac out across Weyard and attempt to pay him back by defeating him in battle. They eventually catch up with Isaac in Shaman Village Cave in Hesperia, when by then Isaac's group has joined forces with Felix's group, and attempt to defeat Isaac and his group in a three-on-eight battle. Perhaps not surprisingly, they lose, and they admit they were wrong in assuming Isaac didn't win Colosso fair and square, since, as Kraden explains, Psynergy is a warrior's talent. They receive Isaac's forgiveness and give him the unique Golden Shirt they found in the cave earlier, and declare they hope to be strong enough to win against him in the next Colosso.