Trauma is a blank card effect with a crazy, twist ending.
Imagine showing a spectator four blank cards.
One of these cards is placed away in a back pocket by the spectator.
You then ask the spectator to imagine that these four, blank cards were Queens, for example, and then to name which Queen appeals to them the most.
After a moment, the three remaining blank cards are shown to have changed into three Queens; except the one card chosen by the spectator.
The spectator now removes the blank card from their pocket to find that it has changed into their named selection.