Hey fellow Final Fantasy X explorer! When it comes to sphere grid progression, I recommend focusing on each character’s strengths. Start by unlocking key abilities like Haste and Curaga early on. Don’t be afraid to mix and match different paths on the grid to create unique character builds.

For side quests, make sure to complete the Monster Arena challenges for valuable rewards and to unlock stronger enemies for grinding. Don’t forget about the legendary weapons and the optional Aeons like Yojimbo and Anima.

When it comes to character builds, consider specializing each character to fulfill specific roles in your party, such as tank, healer, or magic user. Experiment with different combinations of abilities to find what works best for your playstyle. Happy exploring!