Instant transmit to Mayhem or head to the southwestern section of Crimson City and head Northwest. You will need to be at minimum 50m current PL to do this quest.
Head into the bathhouse just to the north to start the quest in the back. You'll find a man named Chiyono. When you see him SAY DOHYO and then SAY FAVOR. You will find the teashouse for this quest just across the street from the bathhouse.
Seek out Takami on the east side of the teahouse building, south of Chiyono. SAY INGREDIENT. He'll say there is a fruit you'll need to SEARCH out. Head west down Mayhem Road and out of the city. Then take the SW exit at the fork. Navigate through the area and head in a general NW to N direction. Once you've found some strange imps you're in the right area. In the Devil Cactus Fields you'll find 'A large, black and red devil cactus grows here.' Type SEARCH.
Once you search an Imp will pop out that you need to fight. Kill him and then you'll have to find him in the desert. If you pay attention to his name it will describe he has a devil cactus fruit. He wanders around a bit so you'll have to look around. Pay attention to what direction he goes in when you kill him to give you a hint.
Once you kill him about 4 times you'll get the fruit. Hurry back to the teahouse or INSTANT MAYHEM and then run into the teahouse. Return to Chiyono with the tea. And you will learn Bodyslam. And with that ticket you'll be able to enter the Dohyo.
Outside the bathhouse head two building west and go north into the Dohyo. In the very back you can pay 100,000 zeni to start a mini event. The event can be completed at any PL because it is against supermobs that require you to be at 100 PL and has a gimmick of setting your character weight so you'll have to use the setweight command.
If you enter the room with the person (Taiho) who starts the quest he'll give you hints about what weight to be at. SETWEIGHT 256 for the magic number to defeat them all. Head to the center of the area to begin the fight. SMOBKILL <name> to initiate. You might not have access to a lot of skills at this PL but Scatter 10 can manage to do a surprising amount of damage early in your career.
I suggest you heal up to full between each fight. Return north to Taiho and complete each round through 5 the same way. After you manage to complete all 5 rounds you will be taught Meteor Strike!