Get her questing ASAP, and if your opponent isnt too far ahead, you might have the game
The fact that Oswald is only 2 cost and can quest for 2 makes it to where you can play him pretty early and start accruing value off his ability real early into the game
At a Regional Championship Qualifier, I once won a game by casting two of these on the opponents end step while they had 10 life a fitting anecdote for keeping in mind what burn spells can be capable of in their best moments
But even without poison, even without Elesh Norn, the set will be important to our format for this reason: Proliferate
Bello, Bard of the Brambles is a Gruul (red-green) legend from Bloomburrow that encourages players to pack their decks with as many cheap ramp spells and expensive artifacts and enchantments as they can, in large part because of his powerful static ability: during your turn, every 4 cost of greater non-Aura enchantment and non-Equipment artifact becomes an indestructible, hasty 4/4 Elemental creature, ready to smash face
Conversely, early print runs or limited-release promos might remain scarce