"I'm getting there." Trunks responded. "Back to the aliens, alright? I told you about the Namekians. I didn't get a chance to tell you about Saiyans." A deep breath--oh boy. "So, Saiyans were also an alien race, who had their planet destroyed by Frieza. Mostly because of two things--Frieza used them as a slave race, where he'd send them to planets where they'd wipe out the current population, move on, and Frieza'd sell the real estate. The reason Saiyans were so good at that though, is because their home planet, Vegeta, had 10x Earth's base gravity. They're natural adepts at fighting and training, offensive ki-manipulation and uses--although not so much sensing but it can be trained--and whatever does not kill them, with enough time to heal, will quite literally make them stronger."

"Frieza destroyed their planet well before I was ever born. Only off-world Saiyans survived, and that number was maybe less than 5?" Trunks knew of only 4 himself, and in his own time-line, he was the last he knew for sure could claim Saiyan blood.