The first level of a card is zero and goes all the way to Lost Ark Gold 5 levels. It grants additional special effects and bonuses that are set when the level is reached.
To upgrade a card's status into the new Awakening Level, you need to perform two tasks. The first is to boost the gauge of XP by feeding it XP or duplicate cards.
It is necessary to continue doing this until the XP bar grows. If it does you must feed it with more duplicate cards to "Awaken" the game (push it over to the next level).
The more advanced the Awakening Level the greater number of duplicate cards you'll need in order to reach the next level. The duplicate cards needed by each Awakening Level are listed below.
Awakening Level 1: One duplicate cards
Awakening Level 2: Two duplicate cards
Awakening Level 3: Three duplicate cards
Awakening Level 4: Four duplicate cards
Awakening Level 5: Five duplicate cards
Be aware that there are a lot of duplicate cards to cheapest Lost Ark Gold awaken a card, it's a sensible idea to not feed a duplicated card only to boost its XP count. Instead, it's more efficient to just feed it XP cards.