So they're just random, it's not like I can go anywhere and fight for them, or trade for 'em or even buy some? I don't think I'm far enough to have encountered those types of enemies yet.

Thanks.

Another question...if I have Rikku "mix" some tablets--the things that make enemies drop certain spheres (ability/power/mana/speed), will they instead drop something good? I got more ability/power/mana/speed spheres than I know what to do with.

And I don't have any level 3 key spheres at all, in about ten or twelve sphere levels, Auron is gonna be blocked off.