Add X counters to your Resource, where X is the number of arenas with a Villager in it.
Keywords
Alternative Cost
Alternative Cost: [cost]: A selective, static effect that means, "Instead of paying the build cost of this card, you may complete this card by paying the [cost] listed." Alternative Cost must be paid in full, if it is not possible to pay the [cost] completely, you can't complete the card. You must pay the [cost] in the order listed. Any ability that reduces the normal cost to complete a card does not reduce the [cost] in that card's Alternative Cost, unless the ability specifically says so.
Lucky
Lucky X: A cumulative, static ability that means, "Each time this unit attacks or is attacked, you may re-roll up to X of this unit's attack dice or have your opponent re-roll up to X attack dice against this unit." Both players can use Lucky effects according to the rules for POP chances. Lucky is used only once after all triggered re-roll effects resolve. You can't re-roll more dice than are rolled for the attack. You may choose to roll any number of dice up to the Lucky value.