4x Morose Harpist (creature, 0/4 prowess, drains equal to power on noncreature cast, 1UB)
4x Surging Kalak (creature, 2/2 hexproof, gives your creatures +3/+3 whenever they're targeted by a spell, 1GG)
2x Fierce Instinct (instant, +2/+2 trample, G)
4x Vampiric Appetite (enchant creature, +3/+3 vanishing 3 sac both, B)
4x Groundswell (instant, +2/+2 landfall +4/+4, G)
2x Infuse Vitality (instant, base p/t 5/5, 1G) 2x Change of Fortunes (instant, target creature -1/-2, target creature +2/+1, 1B)
4x Soul Leak (instant, destroy target creature unless pay 3, 1B)
4x Duress (sorcery, discard noncreature nonland, B)
2x Ambitious Dreams (instant, cripple 1U, draw two, 3U)
4x Travel Companions (sorcery, each player tutors a creature to hand, 1G/W)
3x Fungal Mire (swamp forest, tapped unless matching basic)
3x Lush Oasis (forest island, tapped unless matching basic)
4x Wayfarer's Shrine (pay 1 sac to tutor an untapped basic)
3x Amber Hills (g/w shockfetch)
3x Flooded Depths (u/b shockfetch)
4x Grim Bastion (b/g shockfetch)
2x Forest (forest)
1x Swamp (swamp)
1x Island (island)
The central idea of the deck is fairly straightforward. Get Morose Harpist and/or Surging Kalak onto the battlefield, through pump spells at them, and win the game. Between the two, Morose Harpist is the more reliable win con, letting you drain your opponent for stupid amounts as well as swinging in, acting as a powerful multiplier effect. Surging Kalak is far less likely to win your the game solo, but also has hexproof, so is at least able to sit around safely while you get your stuff together.
Duress helps get rid of any interaction your opponent may be holding, while Soul Leak keeps aggressive decks from killing you before you're ready. Change of Fortunes is nice in that it works both as a pump spell and a removal/stalling spell. Even if you're forced to target your own creature twice, it works out to +1/-1, and power is all we really care about for this deck.
This deck doesn't use the UB check dual, due to my personal philosophy on working with these lands. As is, I can grab a single basic Forest and then grab my duals with wanton abandon (choosing green as the primary color due to Surging Kalak needing double G). Including the UB dual would mean it would enter tapped if all I had was a basic Forest. I could grab a Swamp or Island to let it enter untapped, but then my Lush Oasis's and Fungal Mire's would enter tapped (respectively).
Couple of other notes: Infuse Vitality, despite being a powerful pump spell (effectively +3/+3 or +4/+1 depending on the creature) is only a two-of due to being terrible in multiples. Similarly, while I kind of want to take out the two Fierce Instincts in favor of two more Change of Fortunes to give me a broader removal suite, they work better with the green focused mana base, and the trample can be a very relevant finisher.