The [url=http://destinydevs.github.io/BungieNetPlatform/docs/DestinyService/GetPublicAdvisors]GetPublicAdvisors[/url] hasn't been updated with the April Update changes yet, probably because you can now query advisors for any given character with [url=http://destinydevs.github.io/BungieNetPlatform/docs/DestinyService/GetAdvisorsForCharacter]GetAdvisorsForCharacter[/url]. This will also return you progression information for that character. The current King's Fall Challenge modifiers are not represented anywhere in the APIs and the solution I came up with was calculating the current week since challenge mode came out and then applying % 3. Grab the activityDefinition skulls and filter out alternating weeks (keeping in mind the Heroic skull is always present on hard). I'd also recommend looking at using the new "activities" property which tries to pull all of the advisor data (and events) into a single generic structure and will eventually replace all the individual custom properties.