Hey fellow Final Fantasy X explorer! When it comes to sphere grid progression, my advice is to focus on maximizing each character’s strengths. Try to stick to one path for each character to unlock their most powerful abilities sooner. Don’t be afraid to backtrack to grab important nodes, like stat boosts or new skills.

For side quests, make sure to complete the Monster Arena challenges for great rewards and tough battles. Don’t forget about the Celestial Weapons quests for ultimate weapons – they’re a game-changer! And if you want to tackle the Dark Aeons, be prepared for some serious challenges.

As for character builds, customize your sphere grid based on your playstyle. Whether you prefer physical attackers, magic users, or support characters, make sure to allocate your spheres wisely to enhance their strengths. Experiment with different strategies to find what works best for you. Happy exploring!