In the Valkyries' Citadel, you can improve the characteristics of all types of troops: melee, ranged, cavalry, killers, siege, and scouts.

Initially, the cost of upgrading is roughly the same for all 6 types of troops, but once you have upgraded one type, the cost of improving the others is increased.

After the first upgrade (let's say, for example, that you chose melee troops), the cost for the other troop types (ranged, cavalry, killers, siege, and scouts) will increase to level 2.

When you perform the next upgrade for a new troop type, the cost to do so with the other types will be increased. For example, let's say you chose killers after melee troops; doing so will increase the cost of upgrading ranged, cavalry, siege, and scouts to level 3. Yet another troop type upgrade will increase the cost to level 4, and so on.

So choose wisely which troop type to select first — upgrading it will be much cheaper.

The higher the cost level, the more Influence points and Hero's and Shaman's experience you will receive when the upgrade is completed.

Increasing the Valkyries' Citadel's level gives access to warrior upgrades of higher tiers. In the building, you will find an upgrade tree for each troop type. In order to get detailed info on an upgrade, press its icon.

You can upgrade warriors for resources or instantly for Gold. Help from the Clan members affects the warrior upgrade process. If you decide to cancel the action after the process has started, the resources spent won't be returned.