Elixir of Experience

Elixir of Experience is a treasure that can be obtained by through the Medal Exchange Center. Unlike other treasures, this treasure badge's color is black and its grade is unknown. However, the treasure has five different "sizes": S, M, L, XL, and XXL.

This treasure is an "Effect" treasure, which means it is a "One Time effect treasure" that is cannot be equipped, upgraded, nor evolved, but can only be "used" to boost XP. Currently, it can be obtained from buying in Medal Exchange Center, a reward from a Fortune Cookie, or completing a mission in Tower of Frozen Waves.

Trivia

 * This treasure was the first one which confirmed the name for Tower of Frozen Waves, because it was stated in the Collection Method before the release of the Special Episode.
 * This treasure cannot be upgraded.
 * This treasure cannot be equipped. Selling this treasure gives you 1 and extracting this treasure gives you  3.
 * This is the first 'Effect' treasure.
 * This is the first treasure that can have multiple "sizes" of the same treasure.