After being resurrected by Babidi, Majin Buu begins to showcase his terrifying and unpredictable power. The Z-Fighters, particularly Gohan and the Supreme Kai, realize the gravity of the threat as Buu easily overpowers them with his childlike yet brutal fighting style.
If you are binge-watching, Episode 140 leads directly into the high-stakes battles involving Vegeta’s sacrifice and the introduction of Fusion. Watch Dragonball Kai 140
Remember that Episode 140 of Kai corresponds to a later point in the original Dragon Ball Z (around Episode 235-237) because Kai removes the "filler" content to stay closer to the manga's pacing. After being resurrected by Babidi, Majin Buu begins