"It's not just the wind. It's not all in your head. And it's definitely something to worry about."
This is my Modern Burn deck. I chose to play Mardu burn because I believe it is the strongest version of Burn in Modern at the moment.
Most of the cards I use are standard for a burn deck. Splashing black gives me four more "Lava Spikes" in the form of Bump in the Night. A few games have been won by a flashed back Bump. Black also gives me some really good sideboard tech. Self-Inflicted Wound is so amazing. It deals with so many threats, Kor Firewalker and Tarmogoyf to name a couple, and keeps tempo. Rakdos Charm deals with Affinity, graveyard interaction decks and any kind of Twin or Zoo deck. Splashing white lets me play Boros Charm in the main board. Having a spell that does 4 damage instead of 3 gives me that extra reach. It also helps me with trading creatures more effectively by making them indestructible or giving a buffed, unblocked Swiftspear double strike for a finisher. As for my sideboard, Kor Firewalker is a must for the mirror match. I chose to keep one Stomping Ground in the deck just for Destructive Revelry. I use Revelry for artifact hate and Affinity decks. Also used against those pesky enchantments Leyline of Sanctity and Splinter Twin for example. I thought of cutting Revelry for Wear / Tear but W/T just doesn't keep tempo like Revelry does.
Sideboard Guide
Affinity: -4 Eidolon of the Great Revel, -2 Boros Charm, -1 Bump in the Night, +3 Destrutive Revelry, +2 Defecting Palm, +2 Rakdos Charm. This SB will help deal with problematic artifacts and any creature swinging in with a Cranial Plating equipped.
Burn: -2 Eidolon of the Great Revel, +2 Kor Firewalker. If my opponent is playing white as well, I would also -4 Bump in the Night +4 Self-Inflicted Wound to deal with their Kor Firewalker.
Jund: -4 Bump in the Night, +4 Self-Inflicted Wound. This SB deals with the only real threat in any Jund deck, Tarmogoyf. If I was playing Rain of Gore in my SB, i would add it here to help with Feed the Clan.
Soul Sisters: -4 Bump in the Night, -2 Eidolon of the Great Revel, +4 Self-Inflicted Wound, +2 Rain of Gore. Soul Sisters makes a rare appearance at the LGS. If I was to find out the deck was being played before the event started, I would -2 Rakdos Charm out of my SB and +2 Rain of Gore.
Twin: -3 Boros Charm, -1 Searing Blaze, -1 Searing Blood, -2 Bump in the Night, +3 Destructive Revelry, +2 Combust, +2 Rakdos Charm. This SB answers anything Twin can throw at you.
Thank you for having a look at my deck. Comments, suggestions and upvotes welcome.