Bribing...

"for lv4 key spheres u will have to bribe. bribe the chimera brains in the calm lands 245,000 gil for up to 4 key spheres from each one. with 2 in each battle that makes a possible 8 per battle. chimera brains are commonly found behind the travel agency in calm lands"

erm.. how do you bribe them in battle?

Use Rikku's Bribe ability and select the amount of Gil you want to use.

Do you even have Bribe?

thanks for quoting me from the other thread :D

yeh it's like the last ability on rikku's section of the sphere grid. shouldn't take too long to get