From the DBZ lore, Broli was born in roughly the same month as Goku, back on their Saiyan home world. And presently, Goku has two kids. Thus Broli and Cheelai are adult mercenaries and Broli gets sent on a mission to kill Goku, the main hero in the DBZ franchise...
Three versions of the colored pic were created. And the two extra nude / NSFW versions were posted at my Patreon...