Hey fellow Final Fantasy X explorer! When it comes to sphere grid progression, focus on unlocking key abilities first before branching out. Make sure to use your spheres wisely and don’t be afraid to backtrack to unlock important nodes.

For side quests, don’t miss out on the Celestial Weapons and Aeons, as they can be a game-changer in tough battles. Also, be sure to tackle the monster arena for some great rewards and challenges.

As for character builds, consider each character’s strengths and weaknesses. Customize their paths on the sphere grid to complement their natural abilities. Experiment with different strategies to find what works best for your playstyle. Happy exploring!