For example, Kwain, Itinerant Meddler has an activated ability that lets you 'pay the cost' of tapping it
Then theres stuff like Nahiris Warcrafting that can target three different card types, and you get pseudo card draw from it
Basically, we know that two-mana two-color Glimpse of Nature isn't good enough for Modern, which suggests that it's at least worth testing the effect at one mana
Card not found is a rare, which didnt see much play, but Card not found was a format defining card for a while, even if you couldnt necessarily use the Spell Mastery
Metal tends to be one of the weakest types overall in the TCG, thanks to Weaknesses to more popular Energy types and a selection of Pokemon thats variable in quality at best
WHATS IN RAVNICA: CLUE EDITION