An online trading/auction house.
I don’t know if this would work or not, but I thought for the benefit of those collectors who have missed out on online mission rewards or any player who wants gold egg only arcs, there could be a trading system;
you put up an arc for trade for a specific Arcadian in return.
im sure there’s some not so avid players who got lucky and won an egg only Arcadian that would happily trade if for a more powerful Arcadian say a starter or hatchling, and I know I as a collector would trade say a dreadwolf for the chance to have a coveted egg only monster.
just an idea.