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
You earn wonder hourglasses by completing missions
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
Lastly, we also gain two incredible stadiums
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
You then exile a Sol Ring or similar early drop problem, before simplifying the board, and slowing down bursty starts