I agree that you should try a WK rush file. However, I believe that you shouldn't use Domina, because in my experience she doesn't work out well. Try either a +2 SP SS, or 40 dmg card while you save up for another Violet x2.
Giant Arthropleurid is also a decent choice.
Another thing to note is the 500 gran specials the week pre-builts are released. Those are amazingly good, and you should always try to have 500 gran about to make sure that you can buy one if one appears.
Keep an eye on card of the week too.
When the end comes, and enemies are rushing in from all sides, I will be at your right hand.