During the event period a Hydra spawns in all your cities. You goal is to banish the Hydra before the time runs out. In order to banish the creature, you have to collect 6 Hydra heads and burn them. Hydra heads can be found whenever you fight it. The fights take time and require some units. Completing fights provides you with resources or favour. Additionally you have the chance to get a Hydra’s head, but there is always the risk to lose all units you sent into the fight. After collecting all 6 heads you can banish the Hydra and collect the final reward.
Where to find Hydra
You can find Hydra in the bay south of your city. There is only one Hydra which you can access from all of your cities.
Send units to fight in order to obtain the 6 Hydra heads. After collecting all 6 heads, you you will be able to burn them and banish the creature. Until you burn the heads, you can still send armies to fight the Hydra and collect more rewards.
How to get the heads
In the portal you can send different attacks to fight the Hydra. Every fight lasts a specific time. In order to start the fight, you need the required number of units. At the end of every fight you are rewarded with some resources and favour. Additionally, you have a chance to get a Hydra head, but keep in mind that there is always the risk to lose all units you sent into the fight.
After collecting all 6 heads you can destroy the portal. Destroying the portal will remove the portal from your cities and a reward into your extended inventory.