I just continue to walk to besaid then a priest(maybe) come and call dark valefor then completely destroyed my party. I also found ixion on thunder plain, shiva on macalania, anima on gagazet, three bug that I think magus sisters at mi'ihen, ifrit in bikanel. I'm doing sidequest and this monster attack me, I even scared to play the game now. I need help on defeating this aeons, I want to know where can I get lots of AP and GIL so that I can takes Yojimbo to party. Can everyone tell me where can I get LV.4 key sphere? I'm playing the international version and the crest I get at gagazet is jupiter, i get mars at farplane.
this is my questions:

1. how do I earn BlitzAce and Attack Reels?(I'm bad at blitzball)
2. which monster gives a lot of AP?
3. which monster gives a lot of Gil?
4. where can I get LV. 4 key sphere supply?(I want to open Doublecast and Ultima)
5. about International differences?
6. what is the most least strategy i must use to defeat dark aeons?