I would consider some cards like Teysa, Orzhov Scion to provide more tokens, possibly knocking out the top end of your deck.

I'm not sold on Seer to be honest. The 1/1 body isn't imperssive enough and doesn't do enough in my opinion to get a slot. I would run another human in its place, or consider something like a recurring dude (Bloodghast) for value,

The mana base is fairly good so I would consider running either a utility land like Vault or a way to disrupt the land decks like Ghost Quarter or tech edge.

For the sideboard, try Stony Silence to beat the artifact decks like Affinity or Tron. Aven Mindcensor to shut off tutors like Pod, tron land fetching and scapeshift. Thoughtseize is good. I might also consider running Sword of Light and Shadow as a way to grind more late game and get more value versus jund decks.

Tragic Slip ?

Lingering Souls , Sword of Fire and Ice , Sword of Light and Shadow , Dismember , Oblivion Ring , Night's Whisper .

overall, you have far too many creatures, and not enough instants and sorceries. aggro decks dont even typically run this many creatures. i understand the human theme, but tribal is usually too slow in modern. if you took out the Champion of the Parish es, the Xathrid Necromancer s and added cards that do similar things, but are overall better; you should wind up having a better deck. swords will also help you swing for game earlier and control the board state easier as right now, you dont have anything that can get big aside from the champion of the parish. Mirran Crusader also loves swords.

I'd consider cutting some the creatures, 32 is a bit much, but otherwise nice deck. +1.

The deck needs some removal. Damnation , Day of Judgment , Merciless Eviction , Hero's Downfall , Unmake , Murder , Doom Blade , Celestial Flare , Path to Exile , Swords to Plowshares , anything that can remove creatures in case the tides of battle aren't in your favor.

Crap, didn't notice you already had Path to Exile . Still, it could really use some board-clearing cards, because those are where your Blood Artist s really shine.

Killing Wave over Viscera Seer , does the same thing in sacrificing, but hurts your opponents more and gets rid of threats. take a look at my deck Orzhov Haunted House was a spirit token deck, haven't thought to change the name, now it's humans. and I disagree with dandugg about the tribal not being as competitive. Most people focus on the 'theme' more over being strategy based. Which is why most people fail. :)