MTG Foundations is a new Standard set with a twist its going to stay in Standard until at least 2029, meaning, as the name suggests, the cards within it will be the building blocks of the format for years to come
Arcavios, and Strixhaven University in particular, is all about knowledge of magic, so it seemed only right for a giant spell to be the thing that saves Arcavios
Dread + Michiko Konda, Truth Seeker + Teysa, Envoy of Ghosts - Can an opponent sacrifice the creature that dealt the damage
Into the Inklands had 18 Enchanted numbered from 205 to 222 so it looks like that could be the same case for Ursulas Return
until the end of the turn, it cannot be destroyed by battle and is unaffected by card effects, except its own.