Solomon can be unlocked using the password, 65437205. After that his been entered, he will appear after each Duel that the player wins and award them with a card part and a card.
The following cards awarded by Solomon, after the player defeats any character. The chance of winning a card is indicated by the "%" (chance out of 100) and "2048th" (chance out of 2048) columns. Each listed card has an equal 1/128 chance of being awarded.