A LEGENDARY SUPER SAIYAN's instincts are a bit more than just to fight and to be the very best. A LEGEND already IS the best, by their very birthright.
"What is best in life"
To crush your enemies, to see them driven before you, and to hear the lamentations of their women. Then to spend a looong time dismembering them for having the gall to be your enemies, repeating the same of their women and devouring what remains as you burn the planet to ash. Then destroy the ash, for it is a reminder that someone had the temerity to oppose you.
To own everything you do not destroy. To crush your Rivals beneath your feet and make them beg for mercy, then let them live out their days in worship of your gloriousness while suffering indignities in a fate worse than death.
Everything you see is either Yours or less than worthless, an actively abhorrent stain upon Your Universe.
If you want to be a LEGENDARY Hero, try and find a way to mindwipe yourself and undergo enough mental conditioning you are no longer Gossard as you see him now, but a new boy in his skin. The best, absolute best, you can be is a mildly sadistic anti-hero who has achieved enlightenment in his quest to tame his primal need, and even that isn't quite enough, with an entourage of Morality Pets that you act heroic around to please them.
You are currently a child, all of that destructive instinct is still building within you, not yet surfaced but its there, craving to be tapped into, whispering seductive promises of carnage.