Gustavo 3, also called Gus, is one of Lucia Mar's two Rottweilers in the Earth crawl. He is the smaller dog beside Cici, but his size gives little indication of the danger he presents. Gustavo can discharge lightning from his mouth, fights alongside Lucia, and sometimes attacks without her effective control. Lucia later describes him as the more dangerous of her two dogs. After Cici dies on the sixth floor, Gustavo remains with Lucia until a ninth-floor confrontation in which he nearly kills Mongo and is killed by Rend.
Early appearances and public reputation
Gustavo first appears to Carl through footage of other crawlers rather than in a direct encounter. A program showing Lucia's progress depicts the girl and both Rottweilers tearing apart a large spider. Later images identify the dogs as Cici and Gustavo 3 and show that one has acquired a chainmail-like garment while the other can shoot lightning when it barks. The sequence establishes the animals as active dungeon combatants before Carl knows them personally. Carl guesses that the numeral in Gustavo's displayed name distinguishes him from earlier entrants with the same name, but that is his explanation of an unfamiliar naming convention, not a confirmed history of the dog.
Another early broadcast shows Lucia and both dogs fighting red, demon-like monsters while Lucia uses her mace. The dogs' appearance in these reports places them within Lucia's combat unit: they are visible participants in her victories, rather than background pets accompanying a highly ranked crawler. The images also give other crawlers a way to recognize them before they have to face them. Gustavo's lightning is especially distinctive because it lets a Rottweiler threaten targets beyond the reach of his teeth.
The crawl's entertainment programs turn the dogs into part of a manufactured rivalry with Princess Donut. A news segment advertises a supposed challenge between Donut and Lucia's pets, naming Cici and Gustavo 3 together. Donut objects that she never issued such a challenge. On a separate arena program, footage shows Gustavo and Cici mauling a small animal while an audience cheers; Mordecai cautions Carl that the fights on that show are not real. Lucia threatens to let the dogs tear Donut apart in the dungeon and calls Gustavo Gus. The proposed televised contest is not an actual duel between Gustavo and Donut. It is publicity that amplifies the danger of a future encounter and treats Lucia's companions as attractions in their own right.
The stairwell station and fourth-floor deaths
By the time Lucia reaches a stairwell station with Florin and Ifechi present, Cici has grown to almost twice the size of Gustavo. The smaller dog nevertheless plays a direct part in Lucia's intimidation of the people trying to descend. When Lucia throws a young crawler across the station, Ifechi helps him, and he eventually attempts to escape. Gustavo moves across his route to the stairs. Lightning gathers in his mouth as he growls and takes a step toward the frightened man. He does not have to fire for his presence to make the exit dangerous.
Florin's attempt to draw Lucia's attention turns the confrontation into a brief, violent fight. Both dogs rush him, with Gustavo jumping over the crawler he had blocked and opening his mouth to attack. Florin shoots Lucia, Cici, and Gustavo in rapid succession. One of Gustavo's lightning attacks goes astray and strikes the ceiling as the shots knock the three back. Ifechi is found dead during the exchange, but the scene does not identify Gustavo as her killer; Lucia claims responsibility. Gustavo's established actions are the obstruction at the stairs, the charge at Florin, and the interrupted lightning discharge. Assigning Ifechi's death to him would obscure what the account actually shows.
On the fourth floor, reports about Lucia distinguish Gustavo from Cici again. Louis and Firas tell Carl that the smaller Rottweiler has somehow “accidentally” killed a group of crawlers after a battle. The report gives neither an exact account of the attack nor an explanation of why it was called accidental. It does say that Lucia is subsequently shown alone and sobbing, in a more severe break than the observers had previously seen from her. This incident matters because Gustavo's threat is not confined to enemies in a planned fight. The available report also leaves open how much of the killing Lucia anticipated, tried to prevent, or understood afterward.
The sixth-floor village encounter
Gustavo's most detailed appearance before Faction Wars comes through a recap of Donut's confrontation with Lucia in a sixth-floor village. Lucia arrives with both dogs in her skeletal, melee-focused form. Cici is now roughly pony-sized, whereas Gustavo is still described as a regular-sized Rottweiler. As they enter, Gustavo barks at a dryad and a bolt of lightning from his mouth hits a monkey in the branches on the dryad's head. The monkey falls dead, and Gustavo moves to eat it. Cici attacks the dryad separately. Their different targets show the pair behaving as dangerous individual animals even while moving with Lucia.
The dogs and Lucia later descend toward Donut from a treehouse. Lucia has placed a protection over the village that prevents their dots from appearing on the map, allowing the group to approach without the usual warning. Donut creates a Wall of Fire across their path, and the two Rottweilers retreat in opposite directions from the spreading flames. That division matters to the rest of the encounter: Cici eventually follows Lucia toward Donut inside the burning pub, while Gustavo remains outside. The wall does not neutralize either dog, but it prevents them from acting as one uninterrupted pack.
Samantha becomes the immediate target outside. She hits a teleporting trap and then a snare, which holds her in the clearing. Gustavo seizes her indestructible doll's head and shakes it. Cici tries to take Samantha from him, but Gustavo moves away still gripping her. Lucia, meanwhile, teleports into Donut's path, and both enter the treehouse pub. Gustavo's attack on Samantha is therefore part of a split fight: he occupies her outside while Lucia and Cici confront Donut indoors. Samantha's indestructibility keeps the attack from having the ordinary consequences it would have for a vulnerable head, but it does not prevent Gustavo from carrying her off and continuing to gnaw on her.
During the pub confrontation, Lucia describes an earlier loss in an icy bubble. She says she fell asleep without telling Gus to sleep and recalls friends named Bini, Abraham, and Siti. She calls Gus the bad one, adds that Cici does it too, and says Gus is worse. Lucia also thinks the dogs may have eaten Donut's head-shaped friend, Samantha, and remarks that she received no points for it. Her words are direct evidence of her fear of what the dogs do when she is asleep or loses control. They do not, by themselves, establish a precise mechanism for either dog's behavior or prove what happened to each person she names.
Donut kills Cici by using her Hole spell as the giant dog peers through an opening in the treehouse. Gustavo is elsewhere, still occupied with Samantha, and does not intervene. After Donut escapes, the recap shows him sitting some distance from the collapsing pub and gnawing Samantha's head. Lucia grieves over Cici's body and says Donut killed the wrong dog. In the context of her earlier warning about Gus, the remark marks Gustavo's survival as a continuing threat. It also shows the unequal way Lucia views the two animals: both are her companions, but she considers the surviving, smaller one harder to live with or restrain.
Control and connection to Lucia
Lucia can call to Gustavo and appears to use an invisible leash on him, yet neither fact means she can reliably stop him. The sixth-floor account puts her concern about attacks during sleep beside Gustavo's independent pursuit of Samantha. The fourth-floor report associates his killing of crawlers with Lucia's distress, but does not supply her intent. These incidents support a narrower conclusion than simple obedience or complete independence: Gustavo stays close to Lucia and participates in her fights, while her own statements and the observed outcomes show limits to her control.
The ninth-floor confrontation adds another complication without explaining it completely. After Carl uses a conscription potion on Lucia, a voice identifying itself as Diah says that Lucia is with Alexandro and that Alexandro is present only when the dogs are close. Diah further says that when the dog wanders away, Lucia fades and one of the others can take over. This testimony links a dog's proximity to changes among the people or identities speaking through Lucia. It does not identify Gustavo as a vessel for one of them, define the connection's origin, or establish a rule that accounts for every earlier attack. By this point Cici is dead, making Gustavo the dog immediately relevant to Carl's attempt to understand and contain Lucia.
The ninth-floor tower fight and death
During Faction Wars, Gustavo accompanies Lucia into a tower where she pursues Donut and Mongo. Defensive barrels turn the stairway into a steep, hazardous ramp. Donut reports that the dog keeps sliding away from Lucia and that Lucia has him on some kind of invisible leash. Lucia calls for Gus to come back while Donut throws more barrels. The scene shows both a means of keeping him near her and the practical difficulty of directing him in the middle of a fight. Lucia wants Mongo and treats Gustavo's interference as part of her revenge, while Donut and Carl try to separate dog and owner.
After Carl conscripts Lucia, Donut reports that Gustavo remains stuck below the upper entrance, barking and trying to use lightning. The stairwell hampers that attack. Donut sends clockwork copies of Mongo toward him, but the real Mongo also goes down with them. Carl asks Lucia to summon her dog back. She laughs at the idea that he will listen, particularly at a distance, yet shouts an amplified command for Gus to come. Neither the command nor Lucia's conscription ends the immediate danger to Donut and Mongo.
The fight spills out of the tower when Gustavo, Raul, Carl, the real Mongo, and several clockwork Mongos tumble down the chute. Raul is badly injured, and Carl notices signs that he has already been struck repeatedly by lightning. Gustavo fires another bolt from his mouth and destroys one of the clockwork dinosaurs. A larger divine battle is taking place nearby, but the immediate contest remains between Gustavo and the animals trying to stop him. The decoys delay the encounter without keeping the real Mongo clear of the dog.
Mongo bites Gustavo's hindquarters as Raul moves to seize the dog's head. Gustavo responds with Porcupine Defense: steel quills erupt from his body and impale Mongo, including inside his mouth. When Mongo recoils, the quills pull Gustavo away from Raul's attack. Gustavo then discharges lightning while still caught in Mongo's jaws, sending the already weakened Raul out of the fight. He electrifies the quills again, drives Mongo's health sharply downward, and finally lunges for the unconscious dinosaur's neck. The sequence combines his familiar ranged lightning with a close-range defensive spell, making a successful bite on him dangerous rather than decisive.
Carl cannot reach Mongo safely while a gale tower is firing at him. He calls Rend toward himself and has him activate Wrecking Ball. Rend rolls through Gustavo on the way to Carl, destroying the rear of the Rottweiler's body and killing him before he can finish Mongo. Lucia then kneels by the injured dinosaur and pours a pet healing potion over him. Mongo survives with very little health remaining; afterward, he is still missing feathers around his neck where Gustavo hurt him. Gustavo's death removes Lucia's last Rottweiler and ends the immediate attack, while the damage to Mongo makes clear how close the fight came to a second pet's death.