Let's take a look:
3 Cleric of the Forward Order
2 Anointer of Champions
2 Knight of the Pilgrim's Road
2 Topan Freeblade
2 Stalwart Aven
2 Valeron Wardens
2 Citadel Castellan
2 Sentinel of the Eternal Watch
1 Hixus, Prison Warden
1 Heavy Infantry
1 Patron of the Valiant
1 Outland Colossus
1 Vastwood Gorger
Non-Creature Spells (13)
2 Wild Instincts
2 Enshrouding Mist
2 Mighty Leap
2 Grasp of the Hieromancer
2 Knightly Valor
1 Titanic Growth
1 Vine Snare
1 Valor in Akros
1 Evolving Wilds
Outland Colossus, on the other hand, is a big huge Renown creature that can become a 12/12 fairly easily. He also can't be blocked by more than one creature. The primary issue here is that he can be chump-blocked all day. Obviously, though, if this guy gets a clear path through, he's going to pretty much end the game.
Cleric of the Forward Order is the first non-rare creature we'll take a look at and it's an interesting one. When it enters the battlefield, you gain 2 life for each creature you control named Cleric of the Forward Order. The good thing about this is that you gain 2 life no matter one, potentially being able to gain up to 6 at one time with this deck. For a "bear" - that is a creature that costs 2 mana and has 2 power and toughness - this is okay.
Anointer of Champions is a cute little card in that she can tap to give a target attacking creature a +1/+1 boost until end of turn. It can let you win battles that you wouldn't otherwise win and can make combats a bit trickier. Typically I'm not a huge fan of visible combat tricks, but it can make your opponent overthink how to block or not.
Knight of the Pilgrim's Road is a fairly vanilla 3/2 for 2W, but it does have Renown. That means as soon as he can connect with a player with combat damage, he gets a +1/+1 counter. a 4/3 for 2W is pretty solid, but you have to get through.
Topan Freeblade is a 2/2 with Vigilance and Renown for 1W, making him a bit more efficient than the Knight. Stalwart Aven is only a 1/3 for 2W but he flies and has vigilance, so the chances of this becoming a 2/4 flyer is pretty good.
Valeron Wardens has great synergy with other Renown creatures because not only do they have Renown, but it has Renown 2, gaining 2 +1/+1 counters instead of one. That means being a 1/3 for 2G isn't so bad, because the Wardens become a 3/5. Plus, the Warden allows you to draw a card each time one of your creatures becomes Renowned. This includes the Wardens. Getting a 1/3 through, however, can be a challenge.
Citadel Castellan is one of the better Renown creatures. While I'd recommend cutting it in the Clash Pack deck, in a dedicated Renown strategy, you can't really beat this. Already a 2/3 with Vigilance for 1GW, the Castellan has Renown 2 as well. A 4/5 for only three mana that also has Vigilance is pure value.
Sentinel of the Eternal Watch is a good way to make sure some of your Renown creatures get through. It has vigilance and at the beginning of each of your opponent's combats, you get to tap a target creature that player controls. This is all well and good but this is a 4/6 for 5W. It's not going to hit the board until late, so it's hard to say just how effective this would be.
Heavy Infantry is similar to the Sentinel in that it can tap down a target creature, but only when it enters the battlefield. It's a otherwise a vanilla 3/4 for 4W. So creatures that tap others down are clearly not very mana-efficient in this deck.
Patron of the Valiant is a particularly interesting card, however. When it enters the battlefield, you get to put a +1/+1 counter on each creature you control that already has a +1/+1 counter on it. It's also a 4/4 flyer for 3WW, which are solid stats. It's probably the best non-rare card in the deck, and is a good friend of Renown creatures. Vastwood Gorger is a big fatty, a 5/6 for 5G, which though it has worthwhile stats in a Limited environment, should be replaced by a second copy of the Patron.
Wild Instincts is a bit of an overcosted "fight" card. It costs 3G and gives a target creature +2/+2 until end of turn and causes it to fight a target creature an opponent controls. It's similar to a card called Hunt the Weak from Fate Reforged. That card has the same casting cost, but gives the creature a +1/+1 counter instead of the temporary +2/+2 boost. The best card for this slot, however, would be Dromoka's Command, which can do the same thing as Hunt the Weak for only two mana, and give you other choices, as well.
Enshrouding Mist is awesome for Renown decks. Not only is it a one-mana combat trick that gives a target creature +1/+1 and prevents any damage done to it, if that creature is Renowned, you get to untap it. Mighty Leap is a Limited favorite that gives a target creature +2/=2 and flying until end of turn for 1W.
Grasp of the Hieromancer is an Aura new to Magic Origins. It costs 1W and gives the Enchanted creature +1/+1. But it does something even better for the case of Renown: whenever that creature attacks, you get to tap down a target creature an opponent controls. Knightly Valor is another new Aura, but it costs 4W, creates a 2/2 Knight token with Vigilance and gives the Enchanted creature +2/+2 and Vigilance. While that does a lot, playing an Aura for 4W is rarely a good plan outside of Limited.
Titanic Growth is a poor man's Giant Growth because Wizards doesn't want to print cards that give a guaranteed +3/+3 for a single Green mana anymore. Vine Snare is a conditional "Fog" card that costs 2G and prevents any damage dealt by creatures with power 4 or less. That can be an absolute blowout if you already control creatures that can then block and kill the attacking creatures without a second thought.
Besides the Grasp of the Hieromancer, the other interesting Enchantment in the deck is Valor in Akros. It costs 3W to cast, but whenever you play a creature, all creatures you control get +1/+1 until end of turn. This includes tokens. It's sort of a poor man's Cathars' Crusade, which would put +1/+1 counters on your creatures rather than just the temporary boost. Alas, that card is from Avacyn Restored and long out of Standard. But this is still a good Enchantment nonetheless, especially if you can play multiple creatures in a turn.
Lots of tweaks are to be made here.
3 Consuls' Lieutenant
3 Anointer of Champions
4 Topan Freeblade
4 Valeron Wardens
3 Citadel Castellan
3 Patron of the Valiant
2 Outland Colossus
Non-Creature Spells (14)
4 Dromoka's Command
4 Grasp of the Hieromancer
3 Enshrouding Mist
1 Titanic Growth
1 Vine Snare
1 Valor in Akros
4 Blossoming Sands
We'll add another Anointer of Champions, but we could also replace all three of them with the 2/1 Dragon Hunter from Khans of Tarkir. But the ability to help us win some extra combats seems to make the Anointers okay to include here.
Topan Freeblade is maxed out in favor of Knight of the Pilgrim's Road. Valeron Wardens are also maxed out to take advantage of the card draw and Renown 2. Another copy of Citadel Castellan is added, as well. Gone are the Stalwart Aven and Heavy Infantry. Two copies of Patron of the Valiant replace the Sentinel of the Eternal Watch. One more Outland Colossus replaces the Vastwood Gorger. Hixus, Prison Warden also comes out for not having real synergy with the deck.
These are obviously only suggestions to make the deck function better as is. You could easily include creatures with the Bolster mechanic, such as Anafenza, Kin-Tree Spirit and Dragonscale General to improve upon the +1/+1 counter theme in the deck. You could put in Dromoka, the Eternal and her Bolster 2 ability in, as well.
There are many ways that this deck could be improved upon. What direction do you believe you would take in upgrading the Brave the Battle Intro Pack?