After having had a try on Mono Fire and Mono Shadow, here is my idea of a Mono Justice:
The main goal is to get out
Xulta Loyalist and/or
Paladin Oathbook, as they share the same effect and can pump up your small units to become real monsters.
Xulta Loyalist is a real beast. A 7 Drop (IMO it should be 6 or 8 to be available for Evenhanded Golem :) ) that can be shift played at Turn 3! The +1/+1 is sticky, which makes it extremely valueable in early game and once it emerges you get a nice 7/7 Unblockable Endurance.
Paladin Oathbook - Same effect as
Xulta Loyalist, just as Relic.
Lingering Influence - 1 Cost, 1 Sigil draw + Scout
Hojan, Crownbreaker - A well known unit. There aren't that many cards in this deck to trigger his 2nd ability, but most of the time its not necessary, as Xulta and Oathbook + Empower make him extremely powerful anyway and the Lifesteal seems more important in Gauntlet anyway.
Copperhall Bailiff - Obvious inclusion in Gauntlet, negates those silly 1 Drop aggro decks.
Icaria, Valkyrie Captain,
Valkyrie Enforcer,
Silverwing Familiar and
Amilli, Cloudmarshal - to have some presence in the air. Silverwing profits from the Xulta Oathbook best.
Retribution - vs. Reanimator
The remaining cards in the Deck are obvious choices (to me atleast)
Market:
Vanquisher's Blade - is mostly for Hojan and/or necessary removal
Copperhall Bailiff - just in case you don't draw one from the normal deck
Avigraft - I put it in, because sometimes there are threats i'd prefer to only kill once (Vara....)
Harsh Rule - Board clear
Telut, Queen's Hand - I hardly ever pull him from the Market, as he is not really necessary, so there is a exchangeable Slot
Starting Hand:
2 Power (one should be justice), Lingering Influence, Defiance, Hojan/Icaria, any 3-Drop and Xulta Loyalist/Oathbook
Use ur Lifesteal units wisely, as sometimes they may decide whether you lose or win.
Don't randomly drop a Hojan, if you can't stick him on the board.
Reinvirogate is NOT a Hojan exclusive
Be decisive on which units you want to pump up with
Paladin Oathbook and
Xulta Loyalist.
Don't rush a victory, play it safe, you can spare an additional minute and win on turn 8 instead.
Have fun