Personality Hold everything! There's something about this character that makes him different from all the others: there are two Trunks's: Future and Chibi / Present. They are both the "same" person, Vejita and Buruma's son, but from different chronological moments.  Future Trunks is from a near future, where Earth is ruled (and trashed) by Dr. Gero's artificial humans, #17 and #18. He was taught how to fight by Son Gohan, whose father, Son Gokuh, had died from a heart disease. He came back in time, to the present, to kill a regenerated Freeza and his father, King Cold, and to warn the other fighters of the arrival of #17 and #18 and of Gokuh's eventual death. He supplied the medicine that could, and did, prevent this. In what could be called another "time layer", Cell took advantage of Trunks' voyage back in time and killed him to use the time capsule himself. He did it because he couldn't find #17 and #18, whom he needed to absorb in order to evolve into his perfect form, and that's how he got into present history. Actually, he couldn't find the artificial humans because Trunks had killed them, after training in the Room of Spirit and Time and returning to his own time with improved skills. After Cell was killed in the present, Trunks went back to the future (no pun intended) and, knowing that Cell was going to kill him to go to the past, he surprised and killed him. Confused? You'll understand better if you watch the series. He wears a jacket with the Capsule Corp. logo on it and owns a sword. Anyway, Future Trunks has a calm personality. He's wise, experienced and quite talented. He loves his father dearly, but their relationship is cold, mainly because of Vejita's personality. He seems to understand the other characters, too, their feelings and their motives.  Chibi Trunks, on the other hand, is not at all like that. Vejita took upon him the task of raising and training Trunks, after seeing the future version of his son. Trunks inherits some of his father's characteristics, mainly his pride and his concepts of honour and responsibility. Trunks' best friend is Son Goten, as they practically grew up together. They are not very disciplined, but they are brave when necessary. Trunks is very gifted, as is Goten, and they are the first to try Gokuh's fusion technique. Check Goten's page for a picture of Gotenks, the awesome result of their fusion.

Trunks as a baby Chibi Trunks, 8 years old

 

Future Trunks

Technique I can recall no specific techniques Trunks uses. When Future Trunks appears in the story, he can already reach the SSJ state. He kills Freeza, who had been partially reconstructed with cybernetic implants, with the greatest of ease (see below a picture of Freeza's death). By practising with his father in the Room of Spirit and Time (something that Vejita was not particularly happy about), he increases his powers, and reaches (I think) SSJ2. By the time he returns permanently to his own time, Trunks is capable of defeating the artificial humans #17 and #18 and Cell at his 2nd. evolutionary stage. He is a master in swordsmanship.  Chibi Trunks reaches SSJ very early in his life, as does Son Goten. Their development is, as I have noted several times elsewhere, quite similar. Trunks' fusion with Goten is the most powerful technique either of them can apply. As Gotenks, they can reach SSJ and SSJ3 and use a large amount of spectacularly named techniques that, in the end, do nothing really special. Gotenks' ability to create ghost-like impersonations of himself that attack his/their opponent is one of the few mentionable ones.

Future Trunks in SSJ

Roles in the major battles

Battle against:	Role:	The death of Freeza
Vejita	He wasn't born yet.
Freeza	Wasn't present in the main battle, but killed the cybernetically reconstructed Freeza, by cutting him in half (see the picture on the right). OK, more or less in half.
Cell	He warned about the arrival of #17 and #18, but things didn't go exactly as predicted. Soon, the artificial humans were no longer the greatest danger. It was thanks to Trunks and his time capsule that Cell was able to find them and evolve to Perfect Cell. Trunks tried to destroy Cell before he could reach this state, but Vejita stopped him. In the actual battle, Trunks did no more than resist the Junior Cells and he was killed upon the unexpected return of Cell after Gokuh's Shunkan-Idou.
Buu	In Portugal, we haven't finished watching the series, so I can't yet fill in this section, sorry.