If, for any target, they can't choose a new legal target, then it remains unchanged (even if the current target is illegal)
They can be a little broken, hard to track, or just more powerful than anything youd see in a real set but the one thing they always have to be is amusing
Gandalf in Pelennor Fields Scene There haven't been any spoilers for this one (at least that I've seen), but when they do show up, you'll find em here
The next player (player A), in order, gets to choose if they are getting a land only
Is White your MTG colour of choice
This article explores pregame actions, Leylines, Chancellors, companions, conspiracies, Serum Powder mulligans, Gemstone Cavern, Flash Hulk history, and other strange cards that affect the game before anyone plays a land