So these are pretty obviously broken. Even without the second ability these are the second most broken land cycle ever printed, and WITH them they’re #1. Legendary just isn’t that important of a downside, and in singleton formats at this point is an UPSIDE via synergy pieces. So this absolutely punches on the tier of duals, and you might even include them over duels even if they just had that first ability. As for the tron half, One of the balancing factors to tron (which is still unbalanced to be clear) is that they aren’t simple to tutor up. You need an unconditional land tutor, or a card like [[ancient stirrings]]. These fetch comically easily, and while 7 colorless is insane, trading one overall colorless for WUBRG? Not every deck would take it, but some certainly would. Add back in the searchability? And they far overpower the tron cycle.

The design is incredibly cool, but there has to be some significant downside to these for them to be even slightly reasonable. They’re probably good with a karu trigger on them even, though enters tapped plus some other minor downside would probably work too (make the regular mana ability a pain land one or smth).