Whenever a player would get priority (see rule 117, Timing and Priority), the game checks for any of the listed conditions for state-based actions, then performs all applicable state-based actions simultaneously as a single event
So you can play Basilica Screecher in your Judith deck, because its black and not white
Even cheaper than paying a mana, using a land to give itself shroud is basically the same as having shroud
Quintorius Kand and Urianger Augurelt give you a little life for playing cards from exile, are enablers on their own, and have utility outside of those effects
That we can do this at instant speed and that it is immune to any removal except exile effects makes me think that this combo might just be worth exploring on a competitive front
When Shinyru enters the field, the player selects an opponent, and if they lose, you win