Ancient Adamantoise Any use you get out of Ancient Adamantoise makes it great, because the rebate of 10 treasures is massive and often means you can cast a larger and stronger spell after this
And lets say its some kind of typal deck without quite enough support
There aren't any major rules that are unique to Artifacts, but many cards care about the number of Artifacts you control, or can only target Artifact permanents
That way you can gas up their decks, let them see what its like to pull off explosive plays later in the game, and theyll likely have a lot more fun than if they are totally mana screwed in their first game
6/6 is huge and hitting an opponent one time makes him twice as good, because you'll probably have one or two cards in your yard
In many cases, this adds value to the cards as they will never be seen in a new set again