Hey fellow Final Fantasy X explorer! When it comes to sphere grid progression, I recommend focusing on unlocking key abilities early on for each character to maximize their potential. Don’t be afraid to mix and match different paths to create unique character builds tailored to your playstyle.

For side quests, make sure to complete the Monster Arena challenges for valuable rewards and the Celestial Weapons quest for powerful gear. Also, don’t forget about the optional Aeons and capturing all the fiends in each area for bonus rewards and AP.

As for character builds, consider specializing each character in a specific role like tank, healer, or damage dealer to optimize your party’s effectiveness in battles. Experiment with different paths on the sphere grid to enhance each character’s strengths and cover their weaknesses. Good luck on your journey through Spira!