This recent round of previews showed off some versions of Tifa, Kain from Final Fantasy IV, Squall, Rinoa, and Angelo from VIII, Zidane (with one version being an alternate for competitive powerhouse Ragavan), and Vivi, and even a couple of versions of Firion from the divisive second entry
Artifact tokens, like Treasure, Clue, and Food are considered artifacts in play, and the affinity mechanic doesnt distinguish between token and nontoken artifacts
Sets with only one of those can fade after launch
If Nadu somehow enters the battlefield while a spell or ability that targets a creature you control is on the stack, the ability granted by Nadu won't trigger since that creature didn't have that ability when it became the target of that spell or ability