Muktol

The deck has now a rather strong control component. When playing control I would add some more discard spells like Duress. They remove the threads from your opponents hand and prevent him from even casting them. Of course you need a little bit of card knowledge to know that to get rid of and what your opponent can keep.
24 lands seem to be on the high side so you could add some additional creatures.

What went wrong? Well take a look at the mana-curve ;).
No seriously it looks like you have tried to put 2 deck strategy's into this deck. MonoB Vampire decks normally tend to be an rather aggressive built using "Vampire Nocturnus" to buff your creatures and bypass your opponents defences. Those decks rely on aggressive creatures and cheap (cmc) removal spells.

So if you want to do a vampire sacrificing deck (which sounds like your plan when using "Kalastria Highborn" and "Blood Artist" to back him up) there are some important cards missing. But if you want to play this deck more aggressive then I would recommend lowering your mana-curve and altering your creature list a little bit.

I have done my personal revision of the Vampire Onslaught deck from WotC (http://www.mtgvault.com/muktol/decks/vampire-onslaught-revised/) and also built a B/W sacrificing deck (http://www.mtgvault.com/muktol/decks/wb-tribal-vampire-sacrifice/)

Greetings
Muktol

I would remove "Blood Tribute" as it's far to expensive for what it does, especially if you can get your hands on some "Vampire Nocturnus".
Same thing with "Necropolis Regent". If you want an additional effect like that try "Curse of Stalked Prey"
"Markov Blademaster" has too little support here (removals) to make him really effective.

Some (if not budget price included) suggestions based on my own B/R vampire deck (http://www.mtgvault.com/muktol/decks/rb-tribal-vampire/) and my mono B vampire deck (http://www.mtgvault.com/muktol/decks/vampire-onslaught-revised/)

Vampire Nighthawk (1,5$) , Vampire Nocturnus (4$), Read the Bones, Sign in Blood, Vampire Hexmage, Viscera Seer, Dismember(1$), Tragic Slip

Greetings
Muktol

I would change from "Traumatize" to either "Increasing Confusion" or "Sanity Grinding". Short version: "Traumatize" is just to expensive for what it does.
"Curse of the Bloody Tome" is a card I personally dislike in such decks (save pauper) because milling 2 cards/ round might just be to slow against many other decks. "Chronic Flooding", "Augur of Bolas" or "Mana Leak" could be interesting options.
When using "Hedron Crab" you could also use some searchlands to increase it's effect. This depends strong on your budget because I would use cards like "Flooded Strand" rather than "Terramorphic Expanse" to not slow the deck further down.

Greetings
Muktol

If this would be my deck I would do the following changes to make it a more aggro built:
Sideboard "Blood Seeker"...not every deck you will be going after will play massive creature spells. The fewer creatures your opponent plays the less effective will this card become
Remove "Sorin Markov"...simply to expensive (cmc) for what he has to offer.
Remove "Sorin's Thirst"...when playing aggro your own lifepoints are not that important.
I would remove "Adaptive Automaton" to get another "Vampire Nocturnus" instead

Suggestions:
"Bloodghast"...expensive ($) but a very good card. Especially if you add some searchlands like "Evolving Wilds"
"Vampire Hexmage"...cc2 2/1 first strike and able to kill your opponents planeswalkers by sacrificing him.
"Kalastria Highborn"/ "Viscera Seer"...if your opponent will remove your creatures you can use these guys and gain a little advantage from it.
"Dismember", "Go for the Throat", "Tragic Slip"...some low cmc removal spells
"Read the Bones"...if you need some additional carddraw

I did my personal revision of the "Vampire Onslaught" theme deck from WotC. Maybe you can also take some ideas from there:
http://www.mtgvault.com/muktol/decks/vampire-onslaught-revised/

Greetings
Muktol

Like vaan104 already pointed out, this deck doesn't meet the commander rules.

Take a look at the official site (or at other commander decks) to see how those work and what rules apply to them:
http://magic.wizards.com/en/gameinfo/gameplay/formats/commander
http://www.mtgcommander.net/rules.php

You can always run this deck as a legacy deck but then remove the "commander" tag please.

Greetings
Muktol

I'm not crazy...at last I don't think so. But perhaps the people that don't think they can be crazy after all because every one around them seems to be crazy are the real crazy people themselves... ;)
"Boltwing Marauder" vs. "Butcher of the Horde"...tough choice. I will sideboard the butcher and if I ever get to try out this deck (approx number 50 on the list. Some day I really should get myself an automatic cutting machine to minimize the pain when printing and cutting all those proxys) I will give him a try. Personally I feel that "Boltwing Marauder" will be the better choice here. costs a single mana more to cast but works better with "Dragon Fodder" & co. (at last if you don't need the lifegain or the haste)

I tried to stick to the Khans block to keep this deck in the standard legality as long as possible. But "Raise the alarm" is to valuable to ignore it.
I'm not quite sure how "Mardu Charm" will perform here due to its difficult colour-costs (I only added 2 different "dual"lands so I'm not entirely sure how stable the manabase is)

Thanks for your suggestions.

I'll sideboard "Ghoulcaller's Bell" and "Curse of the Bloody Tome".
"Jace's Erasure" and "Curse of the Bloody Tome" where both cards that I was aware of but I think they might be to slow. Some testgames should tell....
"Counterspell"is one of the best cards but I want to try to keep this deck modern legal. If I didn't want to keep in this legality "Grindstone" or "Millstone" would also be an option instead of "Shriekhorn".

If you like to play a little a bit more control-ish (counterspells and so on) or dislike dual coloured decks use monoU, if you feel that you need some more removal or discard, stick with U/B.
"Sanity Grinding" would be an interesting card for a monoU deck.
A card I just stumbled upon: "Memory Sluice"

The borderpost cards will shift the mana-balance from cc2 to cc3. Also "Myr Superion" will be a problem when adding to many of those artifacts.
Though I use "Trinisphere" it's not guaranteed that I will draw it. Will keep it in mind and see about some testgames.

"Garruk, Apex Predator" would be an option if you have problems with other creatures/ planeswalker's.
Otherwise "Wild Nacatl". But I'm no specialist for casual decks...

Traumatize can't be played earlier than turn 5, that's if you use no ramp/ acceleration, start with 3 lands on your hand and draw 2 additional lands. By this time you will already have removed a great deal of your opponents library, and Traumatize becomes less cost-efficient with every card you remove from your opponents library before you play it.
Thus, for my liking it's far to slow for standard/ modern decks.

Looking good to me.
The question is what doesn't work, or what do you want to do with it? It was a standard deck so it will never be as powerful as a modern/ vintage deck if that's the problem.

Greetings
Muktol

*like*
I would use green/white/blue defender-ramp instead of artifacts here. "Axebane Guardian", "Order of the Stars", "Overgrown Battlement", "Perimeter Captain" and so on. Makes the mana base a little easier, cheaper and safe.
Doing so would restrict your mana-choices a little bit (green is set in this combination) but speed up your play and thus increase your chance of winning.

A long time ago I did a halfdeck with exactly that idea (ramp):
http://www.mtgvault.com/muktol/decks/gw-halfdeck-infinite-mana/

Greetings
Muktol

I would remove "Traumatize" as its to slow and costs to much (mana) to be of great use without acceleration.
"Paranoid Delusions" is also some thing I don't like here. "Tormented Soul" with one "Paranoid Delusions" on it will kill an opponent as fast as it will mill him (1 life = 3 cards -> 20 life = 60 cards). Using 8 slots just for this seems a little bit to much for me. If you want to keep "Paranoid Delusions" then I would change from "Tormented Soul" to "Shriekgeist".
"Wall of Frost" could be replaced with "Kaijin of the Vanishin Touch". Costs less (mana) and forces your opponent to cast his creatures again.
"Augur of Bolas" is a good choice when using many spells

Some other suggestions:
Breaking // Entering, Nephalia Drownyard, Dream Twist, Chronic Flooding

Greetings
Muktol

I would also change from "Infiltrator's Magemark" to "Aqueous Form". Cheaper (to play), provides you with the advantage of Scy and the chances of having two or more enchanted finishers on the battlefield are rather low. Beside the +1/+1 is pretty...weak when looking at "Ethereal Armor"s effect ;)
You might also want to take a look at "Wind Zendikon". Cheap enchantment that provides you with a 2/2 creature with evasion.

There are also some good and cheap duallands, though most (budget) of them have the drawback of coming into play tapped.
Last I would (at last sideboard) some spells that protect your creatures, white offers a wide range for this. If you loose an enchanted creature then all enchantments are gone and you might get into trouble because you don't have enough other creatures or enchantments to buff new ones.

*like*
Some things came into my mind when looking at this deck. I would increase the number of "Maralen of the Mornsong" and perhaps "Nefarox, Overlord of Grixis" to 3 or even 4, at last this is your combo you want to win with and every thing else is just backup. Some tutors or additional carddraw could also help to get things working. My favorite here in monoB would be "Read the Bones"
My own discard (and mill) decks feature at last one card I can remove some of my opponents cards even when I don't have anything in my hand. "Scepter of Fugue" was my favorite choice when I did some of my discard decks.

"Ghost Quarter" would be a must have in this deck. "Smallpox" could also be of interest to you instead of e.g. "Geth's Verdict" or "Undercity Plague" (which is rather expensive to play for my feelings)

Red could also help you out with "From the Ashes" but if you want to use another color than red, green would give you "Fertilid", white for "Path to Exile".

Greetings
Muktol

From my point of vie this deck can't decide if it want's to be more control or agro, fast or lategame. 2/3rds of your creatures are fast (8 creatures with cc2 or less) the other 1/3rd is rather cost intensive (1 with cc3, 3 with cc6). The same is true for your enchantments.
I would decide if this deck should be agro or control first and then try to (re)built it this way. Mixing strategy's is (in my opinion) never a good idea.
You also have some cards in your mainboard that I would rather use in my sideboard....simply because the chance is rather low that you will need those cards every single game. e.g. "Aegis of the Gods": It's an enchantment, yes. It count's towards "Ethereal Armor" effect, yes. But you won't go after a black discard deck or a red burn deck every game and I think (without looking into the database) there will be other and better enchantments/ creatures that might fit into this slot. Don't throw them away but put such cards into your sideboard.

White has access to some rather good enchantment tutors like "Plea for Guidance" or "Lost Auramancers" (I searched for U+W; modern; search for text: search enchantment), if you want to play a more controlish deck those could be real interesting and valuable.

Greetings
Muktol

*like*
With access to black why not use "Infernal Kirin"? I would put it instead of "Kami of Fire's Roar", same cc, 3/3 and evasion.

Greetings
Muktol