Green Knight Armor - It's about what you'd expect, I think. Insanely powerful and insanely difficult to craft. I expect it's theoretically possible that you could craft a full set of Green Knight Armor in 25 lantern years, but that it's probably exceedingly improbable. Like, the Perfect Slayer looks like a rawhide headband next to a full set of Green Armor in terms of difficulty actually managing to craft. That said, individual pieces of the set are really enormously powerful in their own right and, depending on price, the set could be worth grabbing just to have access to the chance to put together one or two bits in a campaign.