AKB, Cat Syncro with Gravekeeper Spy's, is called so because the translations of Arcanite Magician was:
Arcan(arcane) Knight Magician.
Combine this with Beatdown/Beat, and you have ArcaKnightBeat, AKB.
NOT: Arcanite Kitty Beat.
Of course, whoever used this really felt stupid when the english name came out.
Cat Syncro is different. It revolves more around Cat and Airbellum to syncro summon Natural Beast and Balkion, and set up oppression for the evulz.
AKB was also used because it HAPPENED to be also the name of a popular group of idols: AKB48.
No, theyre not good.