Double Skill

NOTE: Cards with a Counter Skill, a Revenge Skill, an Amplify Skill, a Double Boost or a Double Drop are not listed here!

Double Skill combine two Skills and are both activated at the same time when the card is activated. That means two skills from one card slot in your front line. They can have 3 combinations:

2 x Boost, the first Boost stronger than the second
2 x Drop, the first Drop stronger than the second
Boost and Drop, the Boost stronger than or equal to the Drop

A note from Odelgard:

Double Skill cards were released in the Double Edge card pack and are officially the strongest cards in the game. Furthermore, the skills are a combination of boost and drop making them an all around unbeatable at skill 10.

As a note, after much conversation with other players, it is observed that not all of the intended % of the skills is given when the card is activated. This could be a glitch, a miscalculation or even intended by the game.