1. Restart the game and start on easy.
2. When you level up focus on HP and CP and a few sleights. I forget the slight, but there is one where you just fly across the whole room, hitting everyone. As soon as you get that one, dont bother anymore. The rest require summons/magic and other garbage like that.
3. Stack your entire deck with high level keyblade cards. I'm talking level 0, 7,8, 9. Forget summon/magic cards/anything else thats a gimmick.
4. At the start of battle, put down the enemy Jafar card.
5. Mash your way to freedom.
With this set up, it'll be hard for enemies to ever interrupt you. Just keeping pumping it into cp and hp. I would rather have few cards then lots of cards that are low.
Remember, every time you use the triangle option, where you stack 3 cards, you lose one of those cards. So for most of the regular enemies, you can just mash your regular cards, and just reload when you run out, and keep going. Having high level like this plus Jafar makes it hard for them to block you.
COM is a fucking SLOG. I was on the verge of quitting it probably half a dozen times.