This episode captures Krillin’s humanity and courage against adversity so well.And on top of that, it encapsulates Goku.
His unending thirst for a challenge(as he handicaps himself to SSJ1 and SSJ3) and excitement at fighting old foes again hits the nail on his desire to get stronger. His strategic observation allows him to figure out how the apparitions work, reflecting his intelligence when it comes to fighting. But even so, his desire to protect his friends comes first as he spends half of the episode looking for Krillin.
The disconnect between Goku and his friends are made clear when Goku does not understand Krillin’s reasoning for taking up martial arts again.
While Krillin fights for his family, Goku fights to get stronger. But if you lay a finger on his friends, he’ll come after you. The new arc starts next week. It looks like episode 77 is going to be a good one.