So I got the attack reels Overdrive for Wakka and I'm playing Blitzball constantly, but Wakka's other two Overdrives(And his sigil) refuse to show up. What am I missing? I mean I'm at the final boss ffs!
I think you have to register them as an active Overdrive in the menu then get Wakka to train for that Overdrive so that his experience counts towards it...
I seem to remember going through the entire game without any extra Overdrives though, bar one for Auron, one for Tidus and lots for Khimari (which I didn't use).
What are the stats of your characters? If you get Rikku to develop a certain potion with her overdrive, it will double the HP of the characters who are on the field then (I recommend using Auron and Yuna), then you can swap Rikku for Tidus and cast Haste (which you'll need to cast again when it fades) and very slowly grind away at the boss, healing pretty frequently using Yuna - and Auron and Tidus should heal when your HP gets too low or one character falls.
The battle took me 1 - 2 hours, but I defeated him first time.
Play a couple games of blitzball (save after each time) and when the tournament thing comes up, look at the items, if you dont see wakka's overdrives in it, restart the game and look at the items again, should be switching ever time.