This is a seriously stellar product. So many encounters for almost every type of encounter (encounters in the Underworld would've been a really nice section to have), with interesting NPCs, interesting ideas, and some that are almost fully-fleshed out adventures (I ran the Deus Ex Machina encounter and it was very easy to turn it into a full small adventure). Nor is this product something that can be used only in Theros: many encounters in it can be very easily adapted to any fantasy game (doesn't have to be a mythic Classic setting either).