Hey fellow Final Fantasy X explorer! When it comes to sphere grid progression, my tip is to focus on unlocking key abilities for each character first before branching out. This will make your party more well-rounded in battles. Don’t be afraid to backtrack and fill in empty nodes to maximize your stats.

For side quests, be sure to complete the Monster Arena challenges for great rewards and tough battles. Also, don’t miss out on capturing monsters for the Calm Lands Arena and unlocking celestial weapons for your party members. These side quests offer valuable items and help you power up your team.

When it comes to character builds, consider customizing your sphere grid to suit your playstyle. Experiment with different paths to make your characters specialized in magic, physical attacks, or support roles. And don’t forget to mix and match abilities using the customizable ability spheres to create unique and powerful builds. Happy exploring!