You earn wonder hourglasses by completing missions
Contents: 1x Foil Agent of Treachery
This is generally used to balance attacks that otherwise have a low Energy cost, such as "Marowak ex", whose "Bonemerang" can inflict 160 damage for 2 Fighting Energy
Yet the only for sure way to get rare cards is by opening a lot of packs, either twice daily with the games free mode and more beyond by spending hourglasses, or with an additional daily pack with the games paid premium mode
Most of them are pretty fiddly and revolve around combat triggers, with Ink-Treader Nephilim leading the pack as the most interesting (and annoying) of the cycle
Creatures (12) 1 Greenwarden of Murasa 4 Tireless Tracker 1 Emrakul, the Promised End 2 Ishkanah, Grafwidow 4 Contraband Kingpin Planeswalkers (3) Lands (24) Spells (21) Yes, its quite a bit worse than Thragtusk