Kingdom Hearts

• Lightning and healing magic is what you want to cast 95% of the time. Put those in the quick-use menu. In the intro one of the FF10 Babies will ask you something about the time. This affects the experience curve. Dawn means you level up quickly early on but slow down later and night is the opposite with noon being in the middle. I don't know which is more effective but you can beat the post game by level 60-75 iirc so choosing Dawn sounds the most effective.

• The game asks you when your adventure begins. how you answer determines the exp curve. choose Morning, which makes your "regular content" to-next-levels pretty reasonable. the grind to the superbosses at 99 is even more excruciating, however.

• There's a special attack you'll learn as you level up called Strike Raid. this should generally be the only special attack you equip. it's the "core gameplay" special attack that lets you hit distant bosses and knock them out of annoying/dangerous attack patterns. It also gives you some invincibility frames if I remember correctly.