Originally Posted by vivi_ultima
If you can get Steal with Kimahri before Mt. Gagazet, you can steal Level 3 Key Sphere when fighting Biran and Yenke in Mt. Gagazet (Correct me if I'm wrong).
I usually have Kimahri in Lulu's grid, after he learns Bio, I send him to Auron's path and get some defense and strength. Lastly, I'll send him to Tidus's path for better stat. That doesn't matter, I had finished Sphere Grid with him.=)
Wakka's grid is also good. It's a balanced grid, there's magic, magic defense, strength, defense, accuracy, evasion, agility, HP+, MP+ in it.