Many of her followers have attempted to break her out of Avernusand failedbut even while she remains in the Nine Hells, Tiamat can send her aspect to manifest in the Material Plane
I would feel almost entitled to run this in mono white, given the color can still sometimes feel like its punching up, but what makes white decks able to utilize this well is the lifegain that white can do very well
Urzas Cave is again less relevant in EDH than in Modern, where the land subtype is much more relevant
I must agree with a number of the points being made about Lorcana currently
However, this build offers the potential to turn Zur into a creature-focused deck, similar to the way Yisan, the Wanderer BardYisan, the Wanderer Bard is built, though with some obvious and significant differences