With Arhcazia's Island, there were a few interesting legendary cards that didn't necessarily pan out to be as cool as intended, and others that were much better than anticipated
Artifact Color tag templates(None) Sword of Truth and Justice Equipped creature gets +2/+2 and has protection from white and from blue
Yes, you can use the mana from Powerstones to pay for the abilities of non-artifact permanents, just not the spells themselves
Among them is Sami, a 2/4 Human Artificer for four mana, representing the story's human element
Scholar of New Horizons Speaking of additions for mono-white hot damn, this is a sweet card
The ability to sacrifice it to tutor any other land in a player's deck is certainly powerful, though an effective 4 mana (3 + tapping Urza's Cave) to activate is a steep cost in a format as potentially fast as Modern