Hey fellow Final Fantasy X explorer! When it comes to sphere grid progression, make sure to focus on unlocking key abilities for each character first before branching out. This will ensure they are well-rounded and can handle any situation. Don’t be afraid to backtrack to previous nodes to maximize your stats.

For side quests, be sure to complete the Monster Arena challenges for some great rewards and tough battles. Don’t forget to collect all the celestial weapons for your party members as well. They can be a real game-changer in tough boss fights.

As for character builds, tailor each character’s progression to their strengths. For example, Tidus excels in speed and agility, so focus on increasing his accuracy and evasion. Auron is a powerhouse, so beef up his strength and defense. Experiment with different paths on the sphere grid to find the best builds for your playstyle. Happy exploring!