I understand that, but why does they matter? What is the purpose of pointing this out? Is there some de egg per meaning to the relationship?Magic the Gathering now has crossover sets – e.g. they just did one for Middle Earth. There was a crossover set called Adventures in the Forgotten Realms that includes D&D creatures, characters, and places. The Chaos Dragon is from that set. So is the Astral Dragon (which was published for 5e in the Spelljammer book).