Hey fellow Final Fantasy X explorer! When it comes to sphere grid progression, focus on unlocking key abilities for each character first before branching out. Don’t be afraid to backtrack to snag important nodes. For side quests, make sure to complete the Monster Arena challenges for great rewards and work on capturing all monsters for the Arena. As for character builds, experiment with different paths on the sphere grid to customize your party members to fit your playstyle. Have fun exploring Spira!