Basically I was thinking something similar to exodia in Yugioh. There are 7 Dragon Ball cards and you can only have 1 of each in your deck. They are extra cards and are a new color: Orange. I just started playing this game so I'm not sure what would be ok costs for the cards so I'll leave those out. I was thinking this color comes with series 4 which is GT based so we get leaders like Shin Shenron (Awaken for Omega Shenron) that could have effects based around the Dragon Balls. Maybe even Shenron Leader, Porunga, super shenron etc.

Extra Cards:

(1-7)Star Dragon Ball - Discard 1 card from your hand to charge this card as energy during the charge phase. Charge all 7 Dragon Balls as energy and win the game. This card may not be removed from your energy by any effect. (they all are the same 1-7).

Dragon Radar - Look at the top 7 cards in your hand, if any are Dragon Balls add them to your hand.

Black Star Dragon Balls (This would come at a lower cost than Dragon Radar) - Look at the top 7 cards of your deck, if any are Dragon Balls add them to your hand. If the game doesn't end in the next 10 turns you lose the game.

Dende's Blessing -If you have 4 or more Dragon Balls in your energy area, you may look at the top card of your deck and then decide to add it into your life area.

Luminous Glow - If your leader card has "Shenron" in its name, switch two of your dragon ball cards in your energy zone to active.

Lucky Break (Orange Negate Card) - Negate the attack. If the energy used to play this card was a Dragon Ball, return the energy to active (The picture would be when Tao pai pai shot kid goku with the dodon ray and the dragon ball in his shirt saved him)

Super Dragon Radar - Look at all the cards in your life area, if any are Dragon Ball cards add them to your energy.

Precious 4 Star Ball - Look at the top 10 cards of your deck, if any of them are "4 Star Dragon Ball" add them to your energy then shuffle your deck. For each "Goku" in your drop area look at 3 more.

Super Dragon Balls - If your leader card has "Shenron" in its name, you may discard 1 card and look at the top 10 cards in your deck. If at least 2 were Dragon Balls, add all the Dragon Balls you find to your energy.

Interrupting Wish - If you have more life and energy than your opponent, remove all effects of any Dragon Ball cards on the field for the rest of the game (A high cost i would imagine.)

Stone Balls - Remove the effects of any Dragon Ball cards on your opponents side of the field for 3 of their turns.

Namek (Field Card) - As long as this card is on the field you do not have to discard to charge a Dragon Ball as energy.