My pick: Orc Sureshot. This is actually a pretty weak pack. Orc Sureshot is a powerful card with very high upside. Given that you’re taking it first pick, you can prioritize cards that go particularly well with it: Mardu Hordechief, Ponyback Brigade, or Take Up Arms. These are all pretty good cards anyways, of course, but you can make a point to take them just a little higher with an Orc Sureshot in your deck. Without those cards, all your opponent’s 1-toughness creatures can be picked off virtually at will. And even if you’re not outright killing a creature every turn when you’re playing normal creatures one at a time, it can open up the opportunity to make profitable attacks by reducing your opponent’s creatures’ power and toughness.
Not Honorable Mention: Frontier Siege. This Siege looks a lot weaker to me than the others. It certainly has very powerful effects, but it doesn’t seem worth the card or time investment in Limited. Getting two green mana in every main phase is powerful, but unless you’re trying to ramp into 7- or 8-drops, you’re really investing a lot to get that extra mana every turn. Of course, if all the mana came at once, this card would be significantly better. Also, if we somehow had a deck with a vast army of flying creatures, the second ability might prove relevant and could make the card worth playing, but I still wouldn’t spend an early pick on it in hopes of that happening.
My pick: Monastery Mentor. Yeah, yeah. This card is another bomb that can practically win the game with any assortment of random spells, no matter how powerful they are. Getting a 2/2 prowess for three that makes 1/1s which also have prowess likely makes this one of the best cards in the set. If you first-pick Monastery Mentor and draft a deck around it, your opponent is forced to remove it virtually right away or the game could end on the spot.
Honorable Mention: Pyrotechnics. Kickin’ it back to the old school. Pyrotechnics is probably one of the cards that will prove to be so good that it will be the correct pick against even some of the good rares in the set, but not Monastery Mentor. Pyrotechnics will often be able to kill two of your opponent’s creatures, occasionally three, and even rarely four. It has the versatility of being able to kill a 4/4 and even go to our opponent’s life total directly for 4 damage. Pyrotechnics has been one of the best Limited cards every time it has been printed, and this is no exception.
My pick: Flamewake Phoenix. While I certainly wouldn’t put this in the absolute bomb rare category, it’s worth a first pick, and even more so out of this pack which is a bit weak. A 2/2 flying haste for 3 is a very good card, and the fact that if you have ferocious you can return it to play puts it way higher up on the pick list, and makes this a clear pick.
Honorable mention: Hunt the Weak. Hunt the weak is a decent conditional removal spell in a color that doesn’t have access to a lot of creature removal. I wouldn’t be particularly happy to take Hunt the Weak with a first pick, but if the Phoenix wasn’t in the pack, I’d still do it.
My pick: Citadel Siege. This card is an absolute bomb. Both abilities are great, and if this card has only one of the two choices possible, it would still be a first-pick quality bomb. Given its versatility and sheer power, I would never pass it. Two +1/+1 counters every turn or an effectively hasted “tapper” are both absurd, although I’d expect that much more often you’d be choosing the Khans option. Enchantments of this power level are particularly effective since people are not very inclined to maindeck cards that can only remove enchantments in most Limited formats.
Honorable Mention: Mistfire Adept. Mistfire Adept is another card that would likely be a first-pick in many packs, but the pesky rare got in the way again. A 3/3 prowess for 4 is decently powerful, and the ability to give itself and your other creatures evasion really puts it over the top.
My pick: This is another tough one. I think it’s close between Elite Scaleguard and Soulflayer. Both cards have a tremendous upside. Elite Scaleguard is probably somewhat easier to build a deck around, since you can take outlast cards, War-Name Aspirants, or Feat of Resistance even higher than normal. Of course, Soulflayer will occasionally be a 4/4 flying lifelink for BB. My instinct is to lean towards the Elite Scaleguard. I also tend to prefer white over black in this format, which skews my decision a little, but I admit there’s a chance I change my mind after playing a lot with these two cards.