im really good at this game so i thought i could lend a hand.
for riku 4 try using mostly attack cards (dont worry aboiut the value) and put in Jafar enemy card along with 3 cures.
make sure you have absolutely NO premium cards or else youre gonna run iout of cards soon. and every time he uses dark aura, break it emediately with a 0 card ( anything, but prefferably an attack card). and make sure you have a mega elixer from the destiny islands key to rewards. this really helps, especially if you have a lot of cards that you lost over the battle (premiums or combos) oh and try to use as many raids as you can along with a lot of oath keepers and oblivion keyblade cards