The Rainbow Portal will transform into Golden Greed's Domain Portal, inside which you'll find piles of gold and loot, Treasure Goblins, and a boss fight. Can be scanned once per day.
Upon the enemies' defeat, better-than-usual loot will be dropped. Only a single amiibo can be scanned every 22 hours.
This feature works with any amiibo (with the possible exception of those that work with its other features).⇧