Check this Dragon Ball Z: Kakarot (DBZ Kakarot) walkthrough on Majin Buu Saga Episode 4. Including Majin Boo story mission guides, gameplay tricks, boss fight in the arc, location.
Story Progression Chart
See Guides For Other Sagas
[BOSS] Gohan vs. Majin Buu
Use Meteor Sledge To Break
You can decrease the Majin Buu's Stun Gauge and turn him into Break status by repeatedly attack with melee attack and Meteor Sledge.
Look Out For Megaton Bomb
The attack range of Megaton Bomb is too wide to dodge. Use guard to reduce the damage.Learn More About How To Beat Majin Buu
[BOSS] Vegeta vs. Majin Buu
Same Strategy As Before
Majin Buu's moves are the same as before. The only difference is that you will be using Vegeta as playable character. Use Massive Strike to slam Buu in to the ground.Learn More About How To Beat Majin Buu
Train Vegeta Before The Battle
If you haven't had a chance to upgrade Vegeta's skill tree, make sure you do so before the battle with Majin Buu.
[BOSS] Goku vs. Majin Buu
Same Strategy, Use Meteor Smash
You will be using Goku for the third battle with Majin Buu. Use Meteor Smash to brake Majin Buu.Learn More About How To Beat Majin Buu