The short answer is that if you are paying more to kill a single threat card than that threat card actually cost to play you will often end up falling behind
A card is only face down in the exile zone if the effect that put it there specifically says so
This card has only seen one printing from an official set in Magic history, and thats this Urzas Saga version
For me, Breed Lethality sticks out every time I look over the deck list because just about every card is on theme
Koth $1.79 Chandra, Torch of Defiance Emblem // Wizard Token Commander Masters $2.29 Chandra, Fire of Kaladesh Magic Origins $0.69 Emblem (Chandra, Torch of Defiance) Kaladesh $0.79 Chandra, Acolyte of Flame Core Set 2020 $1.29 Chandra Nalaar 2011 Core Set $0.69 Chandra's Regulator (Bundle Foil) Promotional $1.29 Chandra, the Firebrand 2013 Core Set $0.39 Emblem (Chandra, Dressed to Kill) Innistrad: Crimson Vow $3.49 Emblem (Tamiyo, The Moon Sage) Avacyn Restored $0.35 Chandra, Novice Pyromancer Core Set 2020 0 results found