If, for any target, you can't choose a new legal target, then it remains unchanged (even if the current target is illegal)
Instant-include in mono-white decks, but a little harder to justify the more colors you add due to the irreducible triple white in its cost
The One Ring was printed directly into Modern, so it has never been legal in Standard or Pioneer
Roiling Vortex also has a big clause for all the free spells we have been getting recently, with the flare cycle from Modern Horizons 3 starting to make their ways into decks
Y'shtola, Night's Blessed is a Cat Warlock that serves as the face Commander for Scions and Spellcraft, a white/blue/black deck
It is our loss leader for the week, sliding down to $22