Unfortunately, it is available when you have a card with unsatisfactory properties. Please upgrade through this mode. Players have three ways to upgrade card levels and increase EXP points：
Get EXP through PVP battles.
Get EXP potions through the treasure chests won by PVP battles.
Get EXP potions through trading in the market.
When the card's experience value reaches 99, your card will automatically be upgraded to a level, and the attribute value will be increased randomly: POWER, DEFENEC, BONUS REWARD.
*The following table shows the attribute value range of cards with different rarities：
| RARITYATTRIBUTE | POWER | DEFENCE | LEVEL | EXP | TURN | BONUSREWARD |
|---|---|---|---|---|---|---|
| COMMON | 1-30 | 1-30 | 1-10 | 0-99 | 1-4 | 0-5% |
| EPIC | 31-60 | 31-60 | 1-10 | 0-99 | 5-8 | 0-10% |
| LEGENDARY | 61-100 | 61-100 | 1-10 | 0-99 | 9-12 | 0-20% |