This deck is based on something I picked up on reddit with some changes to fit my playstyle.

Was able to get a 1st and 2nd place at my Local Game Store with this deck.

MAINBOARD

1 Drops = You need these goblins to trigger Path of Mettle // Metzali, Tower of Triumph and also speed in for some quick damage with some of the boys. Bonus points for using the fanatics to trigger some easy first strike kills. I'm looking at you steel leaf champion.

2 Drops = Knight of Grace Is the best in class, there are so many different options here all with their advantages and disadvantages, I ended up here because History of Benalia is a monster of a card and knight of grace hangs out with it nicely.

Swiftblade Vindicator Sure she dies to chainwhirler, sure she's a 1/1 for 2, sure she's a magnet for shock. After hearing all complaints I'm back to running this card. This is a card if you give her just a sip of bonus attack she'll hand you 1/4 your opponents life total and ALSO she'll call home and protect your butt against the counter attack. What more do you want? To mentor onto some one one token?

Lightning Strike Is just one of those magic cards you need to run, great synergy with first strike, has fine reach, tried playing more consistant threats and I always come back to this trusty spell.

3 Drops = Tajic, Legion's Edge Yes, yes and more yes. The only downside is that you have to pay TWO MANA to give him first strike. Bet you didn't even read that power huh? Blow out the opponent, trigger path of mettle, mentor on all your duders. Give everyone, save him, immunity to your oppnenets burn which is laughable because HE is the magnet for the spells. And for good reason.

History of Benalia Just drop the hundred dollars and buy this stupid broken good for nothing card and win games without trying. Triggers path of mettle, the knights hang out with tajic at slumber partys. This card is a 3 for 1 that only asks you to pay 3 mana. Sometimes a Win-For-One.

4 Drops = Aurelia, Exemplar of Justice Huge payoff for running Boros. She slices, dices and julliennes (sp?). She buffs the little guys, the big guys. She can get rushed into action with the torch courier if you want. If she gets removed it feels bad. I have toyed with the idea of running Heroic Reinforcements to bring in some serious 4 drop weenie swing. But I come back to this beautiful angel to close out games in the air.

Ajani, Adversary of Tyrants Get back those two drops that are so difficult for your opponent to deal with, or create perfect mentor buffs and make all your dudes go in and swing harder and harder and...you get the drift. Bonus points on vindicator and adanto vanguard.

5 Drop = Lyra Dawnbringer This is up for debate. This deck doesn't have to go to the five drop slow, but path of mettle does sorta ramp you. But if she sticks, you can pretend to be Boros Angels for a minute before you opponent concedes. I just think maybe Heroic reinforcements might be better here. The one thing I can say is your opponent probably used all their removal on the 1-4 slot creatures.

SIDEBOARD

Citywide Bust for mono green stompy matchup as well as boros angels matchup this sweeper is a one sided wipe that really gets you there against those big boys.

Adanto Vanguard Comes in strong against control, really sticky and can get you there. Once you have one on the board feel free to apply pressure with other creatures. 

Tocatli Honor Guard Really is a win-more against GB midrange. But watch this one card shut down their entire deck. Also she is a really nice mentor target as well, 2/4 is kinda sticky and 3/5 is just plain a great investment.

The Immortal Sun Wow, what can I say about this card other than watch your opponents face twist in agony as they keep reading all the abilities on this card. I'd bring it in as a sleeper against control to lock out the planeswalkers and maybe against a grindy GB matchup to lock out all the Vraskas.

Shalai, Voice of Plenty This is really here against Settle the Wreckage But with Tajic it creates a nice synergy to shut down alot of removal.

Deafening Clarion Against the mirror, or mono-blue-tempo. Great synergy with Tajic, I may cut this if I find a better solution in the mirror.