
Here's the list:
Creatures (23)
1 Dromoka Dunecaster
2 Servant of the Scale
2 Dromoka Warrior
3 Lightwalker
1 Territorial Roc
1 Scaleguard Sentinels
2 Sandcrafter Mage
2 Salt Road Quartermasters
2 Champion of Arashin
2 Aven Tactician
2 Sandsteppe Scavenger
2 Enduring Scalelord
1 Arashin Sovereign
Enchantments (3)
2 Pacifism
1 Sheltered Aerie
Artifact (1)
1 Dromoka Monument
Instants (8)
2 Inspiring Call
2 Scale Blessing
1 Enduring Victory
2 Dromoka's Gift
1 Secure the Wastes
Land (25)
1 Evolving Wilds
13 Plains
11 Forest

Bolster is the main mechanic of this deck. This ability gives you the chance to put a +1/+1 counter on a creature with the least toughness among creatures you control. Unfortunately, most of the Bolster cards occupy the higher end of the mana curve in this particular deck.
Still there are some cool cards of note. Servant of the Scale is a useful one-drop common creature that enters with a +1/+1 counter. When it dies, you get to put any counters it has onto another creature. Scaleguard Sentinels is a good creature if you happen to have a Dragon in hand or in play as you cast it.
Sandcrafter Mage is a good creature with Bolster – in Limited. Enduring Scalelord is pretty cool as an uncommon Dragon in a deck that has lots of +1/+1 counters flying around. Having both on the battlefield at the same time allows you to "go infinite" and stack as many counters as you want which is pretty much a win condition.
The best card in this deck, however, is clearly Secure the Wastes. An Instant speed Warrior token generator for only a single White plus X is just really, really good. It's one of the most useful cards of the entire Dragons of Tarkir set. But even its inclusion probably isn't enough to make what's a pretty mediocre Intro Pack deck worth buying.
Dragonscale General is a great way to ensure you get plenty of Bolstering done, too. Perhaps the best creature for this deck, though, is Anafenza, Kin-Tree Spirit. Her Bolster ability activates whenever another non-token creature enters the battlefield under your control. Optimizing the mana-curve towards more efficient creatures should make her even better.
The Massed Ranks Intro Pack is probably still worth buying at its original price just for the Secure the Wastes and two Booster Packs. Still, it's certainly not the strongest choice of the five decks for Dragons of Tarkir. It's also getting pretty hard to find in sealed form. It does at least introduce the Bolster mechanic to newer players and is a fairly easy deck archetype to upgrade quickly.
Updated 2/21/2018