Hey fellow Final Fantasy X explorer! When it comes to sphere grid progression, focus on unlocking key abilities first for each character before branching out. Don’t be afraid to backtrack to grab important nodes. For side quests, be sure to complete the Monster Arena challenges for great rewards and tough battles. As for character builds, customize each one to fit your playstyle. For example, Tidus is great for speed and physical attacks, while Lulu excels in magic. Experiment and have fun on your journey through Spira!