direct access to all quests from children's week completed previous year
The orphans from Orgrimmar and Shatrath (blood elf) directly allow you to take all and any of the quests from the event questline - if they were completed last year. The orc orphan lets you take the finishing quest as soon as you call him for the first time - didn't complete the finishing quest for the blood elf last year, but the second tier ones are avaiable on first summon this year - similarly to the orcish orphan. Haven't completed the Dalaran ones last year to give info on those.
