Trunks runs through Dragon Ball Z, GT and Super in two versions that take turns: the sword-wielding young man from a ruined future, star of the Androids and Cell sagas and later of the Goku Black arc, and the boy born in the present, who becomes the face of the new generation alongside Goten. Trunks's profile covers him by theme; here we follow him saga by saga, keeping the two timelines apart.
Dragon Ball Z
Androids Saga (episodes 118-139)
Future Trunks comes from a world where Goku died of a heart virus and Dr. Gero's androids killed almost everyone. He was trained by Gohan, the last survivor, and in the anime he became a Super Saiyan on finding his master's body. Using the time machine Bulma built, he travels to the past to deliver medicine to Goku. In the Androids Saga his debut is electrifying: in episode 120 he turns Super Saiyan and slices Frieza in half with his sword, then finishes off King Cold too. In episode 122 he tells Goku who he is, the son of Vegeta and Bulma, and hands him the cure.
He comes back months later to find that this timeline's androids are not the ones he knows. In episode 132 he saves the young Bulma and his own infant self from Dr. Gero's attack; soon after, Android 17 knocks him out with ease. Meanwhile, in the present, the other Trunks has already been born.
Cell Saga (episodes 140-194)
In the Cell Saga he is the one who works out that the monster arrived in a second time machine. He trains with Vegeta in the Hyperbolic Time Chamber, where he finds a level beyond his father's but keeps it to himself so as not to wound his pride. He tries in vain to stop Cell absorbing Android 18, even attacking Vegeta, and when his father falls he unleashes his power in episode 163. His bulked-up form, though, is too slow to land a hit, and Cell spares him and announces the Cell Games. At the tournament Cell kills him in episode 188. Wished back with the Dragon Balls, he says goodbye to his parents in episode 193 and returns home, where he destroys Androids 17 and 18 and his own era's Cell.
Majin Buu Saga (episodes 200-291)
The Majin Buu Saga hands the role to present-day Trunks, now a kid. He beats Goten in the junior final in episode 212, even though both have gone Super Saiyan, then knocks Mr. Satan out of the ring with a light tap and sneaks into the adult tournament with Goten disguised as Mighty Mask. When Buu awakens, he fetches the Dragon Radar from Capsule Corporation while Goku buys time, and learns the Fusion Dance: Gotenks is born in episode 251 and later reaches Super Saiyan 3. Super Buu tricks them, though, and absorbs Gotenks in episode 265. Once freed, Trunks dies when Kid Buu destroys Earth, is revived by the Namekian Dragon Balls and helps rally Earth's people behind the Spirit Bomb. A year later, in the first episode of Dragon Ball Daima, his ninth birthday party is the backdrop to Gomah's scheme.
Dragon Ball GT
Black Star Dragon Ball Saga (episodes 1-16)
In the Black Star Dragon Ball Saga present-day Trunks is the reluctant president of Capsule Corporation. In episode 2 Vegeta insists that he head into space with Goku instead of Gohan, and so begins the journey with Goku and Pan in search of the Dragon Balls, with the robot Giru acting as their radar.
Baby and Super 17 Sagas (episodes 17-47)
In the Baby Saga, on Giru's home world, he uses a decoy to uncover Dr. Myuu's plan and try to sabotage it, but Baby still escapes toward Earth; once home, Trunks too falls under the parasite's control and fights Goku. In the Super 17 Saga he travels the globe with Goten to stop the villains who have escaped from Hell.
Dragon Ball Super
Battle of Gods and Universe 6 Sagas (episodes 1-46)
Present-day Trunks goes back to being Goten's comic partner. In the Battle of Gods Saga the two fuse into Gotenks against Beerus and in episode 7 get beaten and punished for mocking him. In the Universe 6 Saga they end up on Planet Potaufeu, where Vegeta goes to bring them back.
Future Trunks Saga (episodes 47-76)
In the future, having stopped Babidi and Dabura and reached Super Saiyan 2, Trunks now faces Goku Black. The Future Trunks Saga opens with his mother's death: in episode 47 Black kills Future Bulma; Trunks flees to the past, where his younger self watches the time machine land. He trains with Vegeta, goes back to his own time and in episode 62 his rage drives him to a new form. In the finale he gathers the survivors' energy into a Spirit Bomb sword and cuts Fused Zamasu in half in episode 66. Zeno erases the future, and Trunks leaves with Mai for a new timeline.
Universe Survival Saga (episodes 77-131)
During the Tournament of Power present-day Trunks stays home: in episode 94 he and Goten are left to guard Android 17's island with Marron, in the Universe Survival Saga.
Movies
In Super Hero teenage Trunks and Goten help Gohan and Piccolo against the revived Red Ribbon Army, and their botched Fusion produces an overweight Gotenks.
Did you know? In the manga Future Trunks is already a Super Saiyan while training with Gohan; it is the anime that ties the transformation to finding his master's body.
Our take
Read saga by saga, Trunks is two characters with two jobs. The young man from the future carries the tragedy: every victory in the past leaves his own world untouched, and when he returns in Super a new disaster is waiting for him. The kid in the present brings the lightness, and Gotenks is proof that the new generation can become incredibly strong while playing around.
The link between them is Vegeta. He stands beside his future son in the Time Chamber, loses his head over him at the Cell Games, and is the one who sends him into space in GT. Following Trunks also means following a father learning to be one.
For the family, read Vegeta saga by saga and Bulma saga by saga; for his best friend there is Goten's profile.