This is my Boros Aggro deck I use in my local FNM Modern Tourneys. Pretty straight forward, but ideal start would be
Turn 1 : Mountain, Figure of Destiny
Turn 2 : Plains, Lightning Bolt or Path to Exile, swing with and level up Kithkin
Turn 3 : Any non tapped land, swing with Kithkin, level up before damage
Turn 4 : Any non tapped land, Cerodon Yearling swing with both holding back Boros Charm to either protect your guys or 4 to the face.
That is up to 19 damage already...
Quick breakdown the cards in my Deck;
Figure of Destiny is the hidden powerhouse of this deck, who doesn't like a cute little 1/1, that can grow into a 8/8 Flying, First Striker.
Lightning Bolt is still the go to card for red burn.
Path to Exile is the best answer for anything bigger than */3 non-hexproof critters.
Boros Charm is utility in a nut shell, from to the face burn, to a creature bubble, to the possibility of a Double Striking Spark Trooper
Cerodon Yearling is an awesome 2-drop, giving good early game pressure.
Lightning Helix is a good utility removal with added Life gain.
Legion Initiative
is a superb 2 cost Anthem, as most of my critters are dual coloured, and the Exile to save is something your opponent has to play around.
Chandra's Phoenix is also a threat that needs to be answered, with more than just killing or countering, as she can keep coming back with the amount of burn we are mainboarding.
Boros Reckoner is a win con, all by himself.
Spark Trooper is a surprise that keeps your foe on their toes.
Deflecting Palm is a great hold back for any deck running a battlecruiser strategy, ie Affinity, GW Hexproof, or Urzatron.
As for the sideboard...
Pithing Needle - for all those pesky Planeswalker decks.
Rest in Peace - for those Control, and Persist-type decks
Elixir of Immortality - for the occasional Mill Deck.
Tempest of Light - for the newly added God's Weapons based decks. Or Hexproof Enchantment decks.
Ratchet Bomb - for Token decks.
Intrepid Hero - For anyone playing against Green Ramp decks, they drop a Primeval Titan, you say 'sure have 2 lands, and then bury your guy'
Stony Silence - is here as my only losses tend to come from one deck of Artifact Affinity.
Assemble the Legion - for anyone playing a slower deck, or looking to control the Mid-game. Can quickly get out of hand, and I don't mind dropping a 0 counter Ratchet Bomb, as I will get more guys next turn.
If anyone could give me some critique on my deck, and any suggestions with explanations it would be brilliant.
Many thanks for looking and +1 if you like it.