If you put Comfort into play in a Realm slot, you may immediately take a bonus Fortify Action in that Realm. It does not count against your allotment of Actions for the turn. You pay costs and use upgrades as usual. You can unlock or upgrade the Action in the usual way.
This is a Mild Emotion. If this Emotion is Empowered, it is replaced with a Strong Emotion called SATISFACTION.
Empower is a Spirit Action available in the Full Game rules.