All cards have their own limits and none can reach EAEE. The best defensive card is Ribbon (0MCF). The best attacking cards are Hades, Excalibur II and Ultima Weapon, all of which have an F for attack. However, when you factor in A type, definitions of 'best' become blurry. For example, an A type Mover (usually 6MF0) would use the F to attack, making it just as powerful as one of the three I listed before.

In terms of the best card overall, I'd say the Nova Dragon qualifies with a potential of EP7C.

On a side note, you can keep training your Viltgance until it reaches EP92.