Upgrade

The upgrade menu is used to combine cards. This will upgrade them and make them more powerful.

(This is the card you will put in the middle Yellow Box) (These are the cards you will put in the outlying boxes)
 * Select a card to be the "base" card. This is the card whose stats will improve.
 * Select a card to be a material card. You can select multiple cards at once.
 * Upgrading also requires Credits in addition to the cards.

Upgrading consumes all the material cards. Only the base card will remain. The process cannot be reversed, so choose your cards with care. Material cards with higher overall ratings and rarity will give greater xp bonuses to base cards.