he copied Gokus entire style on some desiigner shyt using kamehameha foh
he knew all of Vegetas moves but never used a single one (all inferior)
and he didnt kill Goku, Goku sacrificed himself because that fakkit wanted a tournament but got mad when he was getting his ass beat by a kid and tried to blow the earth up
and Goku didnt give up he wanted his son to be the one to defeat Cell to prepare him to be the next protector of Earth because of his absurd potential, he felt guilty only because he never spoke with Gohan about Gohan being the new protector because he assumed Gohan would gladly protect the innocent like Goku always did