Masquerade ball is a more powerful version of Courtly Intrigue. It is commonly used in direct damage decks or decks that have a lot of gold to spend. Though it is cheaper than 2 Courtly Intrigues and only takes up 1 space in the bank, it will combo less than 2 Courtly Intrigues because it only adds 1 non-coin card to your inventory. However if you constantly empty your bank, it is a good idea to play the more powerful cards like Masquerade Balls to get the most out of the bank slot.