Man, figuring out the perfect deck in 'Kingdom Hearts: Chain of Memories' feels like cracking a code sometimes. I've spent hours tweaking my setup, and here's what works for me: prioritize sleights like Lethal Frame and Sonic Blade—they shred bosses. Early game, stock up on cheap attack cards (value 3-6) to build combos, and always keep a few zero cards to counter enemy sleights. Don't forget healing items! Later, swap to high-value cards (7-9) for raw power.
One underrated trick? The Jafar card boosts your sleight damage massively, and Cloud's card lets you spam Omnislash. Also, organize your deck by card value (low to high) so you can chain sleights smoothly. I once got stuck on Marluxia until I realized my deck was too cluttered with situational cards—streamlining it made all the difference.