Can be found inside the locker in the Aurochs& locker room at Luca.
Item #1 (Jupiter Sigil)
Offered as a prize in Blitz ball League matches, but only after Wakka has the Attack Reels, Statue Reels, and Aurochs Reeels.
Can be found in a sand whirlpool in Sanubia Desert.
Item #1 (Mercury Sigil)
Can be obtained after you complete the Village of the Cactuars mini-game and look for a treasure chest in the sandstorm area.
more balloons to grab. It takes a long time to get the hang of it (took me almost 2 hours to get it), but the reward is more than worth the torture. Tidus's weapon, when fully powered, coms with the abilities Triple Overdrive, Evade & Counter, Magic Counter, and Break Damage Limit, so it's definitely worth it.