There have been a few reports of all the player's cards disappearing after getting this card. One of the game creators is supposedly aware of this as of this post on GameFAQs. PROCEED WITH CAUTION.
Your inventory only has space for 48 cards, and so this card never appears in your inventory. Additionally, the spritesheet for card images only has 48 cards, so the graphic for this card is a plain red square (different from Secret 10).
How to Obtain ItEdit
Use the Wiggle Glitch to reach the island from below. This method is very easy.
It's possible to get this card starting in Terminal, and doing a Void Warp. Head East to the broken bridge that is full of holes. Head to the end where the treasure is, and use swap to travel to the east side of the screen two squares below the chest. Jump onto the next screen and you will start falling. Go to Nexus and hope for the best.
You can also use the Noclip Cheat Code to easily obtain this card.