I like Blitzball, but I still think it really overstays its welcome for how simple it ultimately is. 2 halves per game, 10 games per league, is just too much, even using Reset Data to the point it only takes 2 leagues and 2 tournaments to get the sigil (skipping the 2 extra leagues it would take just to get Status Reels and the sigil to show up).

Luck grinding is what made me drop the FFX postgame myself several times back in the day. It truly is tedious. Only when the PC HD Remaster came out with 4x speed and auto-battle did I finally get through it. It helps that you don't need *that* much of it; at least 86 is the sweet spot for the postgame since it lets you consistently hit Penance's arms, overdrives and Aim buffs take care of the rest. During grinding it also helps to do some bribes of Maelspike for 100k Gil to get an Attribute Sphere per, each of which can activate a luck node someone else has already activated; makes for a decent change of pace when you're getting sick of Earth Eater.

I typically get the final Lv 4 Keys just by mugging them from Nemesis myself, the ones you get guaranteed are usually more than enough before that. Also gotta say that while farming Mimics with Gillionaire is fine and all especially while you're still capturing anyways, it's certainly not the fastest way to grind gil in this game. I think the fastest way that also has side benefits of gathering up Dark Matters is one-shotting Sleep Sprout over and over again until you get up to 99 Teleport Spheres (on average also getting about 12 Dark Matters in the process), then filling up your equipment menu with customizable weapons from the Kilika equipment shop, customizing Evade & Counter on them and selling them back (as well as the drops from Sleep Sprout itself), rinse and repeat. Teleport Spheres are also in general a great asset for sphere gridding.