It is used as the currency of the temporary event (anniversary festival) that you can exchange for great items in the event store.
You can get anniversary cards by:
- Collecting resources on the world map during the event period.
- Eliminating the rebel forces during the event.
- New purchase packs during the event period.
- Gift package discounts during the event.
- Super discount packages during the event period.
- Completing daily tasks.
- Daily prizes during the event.

*Note: After the event is over, exchanging anniversary cards of all kinds ends with it.