Lion card

Directions
Make your way to the checkpoint down from the boss room. There will be a room with a giant pit and pink arrow tiles. Activate the arrow tiles and jump diagonally, holding down and left while in the air. Once you can reach the bottom left corner, hug the bottom wall. Step onto the left arrow tiles and jump up to the button. You must be hugging the wall before attempting the jump or you'll fail.
 * 1) Left
 * Up

Once the button is pressed, head down. Activate these arrow tiles and jump diagonally, holding down and right. This is a tricky jump. Past this, defeat the monsters to lower the gate, and head down. Defeat the acrobats to obtain the card.

It is also possible to return after obtaining the swap upgrade, and using it to swap with the chest, bypassing the jumping puzzle.