Final Fantasy X is a typical Japanese role playing game created by Square Enix.
GAMEPLAY HINTS
Defeating the Spherimorph
Have Tidus, Lulu, and Yuna on your team. Use Yuna to cast the Nul spells, then use Tidus' attack. Spherimorph will cast an elemental spell on Tidus. However, if you used the Nul spells it will not harm him. Have Lulu cast the opposite of that spell/ Spherimorph will then use Elemental Shift. Keep repeating this and Spherimorph will soon be dead and you will suffer no damage.
First, equip your heavy hitters with weapons that are non-elemental to prevent Spherimorph from getting healed. Start out with Rikku, Lulu and Tidus. Rikku should be the first one up normally.
Change her for Auron, who should attack with Magic-Break. Spherimorph will retaliate with his spell Counter, so you can easily tell its element. Haste Auron with Tidus , add a Power Break for good measure, and slice away with Auron and Tidus using the warrior mode to get your Overdrives up).
Do not use Auron's Overdrive, as it is elemental in nature. Use Rikku's Overdrive to heal your party with two Potions or switch Lulu for Yuna to heal your party. You can use Lulu's Focus ability to guard from the spells and Tidus' Cheer ability to protect from his basic attacks. When you estimate the Boss has dropped to about 2,000 HP and has changed to Ice element, get Yuna in to grand summon Ifrit so you can overkill easily for extra AP.
Start with Lulu, Yuna, and Tidus in your party. Have Tidus hit the Spherimorph with a non-elemental attack to reveal which element it is currently using. Then, have Lulu cast the opposite spell to force it to use Elemental Shift.
Repeat this process, using Yuna to heal in between attacks, until a Thunder spell is cast. Then, use Yuna to summon Ixion. Use his generic "Attack" command and this will force Spherimorph to use a Thunder spell, which will heal Ixion Repeat this process until Spherimorph is dead.