Its usually less good than an Ephemerate, another card I pick over single-target protection a good amount of the time, too
The "Urzatron" lands, Urza's Mine, Urza's Power Plant, and Urza's Tower, each produce one colorless mana on their own, but if you get all three together they'll make seven
As a result, telling cards from these sets apart can be tougher
If youre bringing lands back from the graveyard it would also behoove you to play multiple lands a turn
Yshtola Rhul: The double endphase is what you want here to get two Dr
There have been a variety of run sizes printed so far, ranging from 513 for The Thirteenth Doctor down to a single card for the 1:1 The One Ring