Apologies ahead of time; this will be a long post. Edgar is my introduction to the commander scene and he came at a great time, since I've been wanting to rebuild my old vampire tribal. A couple things to consider (as I've been looking into it, too).

Regarding the counters, Metallic Mimic naming Vampire would help by immediately pumping any vampires you cast and each token you produce. Cathars' Crusade would be bonkers with Edgar. Mikaeus, the Lunarch boosts all creatures, too. I wouldn't be too concerned with removing vampires for non-vampires honestly. It can still be tribal with a few helpful "thrulls" if the cards work too well not to include. (Also Mephidross Vampire and Voldaren can change them.) Urge to Feed is spot removal with the possibility of pumping.

You could also consider some of the Abzan cards that would benefit all of your creatures with counters on them, such as Abzan Falconer and Mer-Ek Nightblade. I believe Whip of Erebos is strictly better than the Battlepriest, though. Along the same lines, Exava, Rakdos Blood Witch provides another haste card, which is scary (and she fits the flavour while not being a vampire herself).

Other thoughts are the use of Ajani planeswalkers in tandem with (or in place of) some of the Sorin planeswalkers. Fits the flavour? No. Fits the theme? Hell yes.

Final considerations. Anointed Procession is also crazy with Edgar. While it would appear underwhelming on its own, Edgar's eminence effect will always make it a threat. Collective Effort is great utility with versatile removal or pump spell in one. Kalitas, Traitor of Ghet is a pricey card, but amazing. And I feel Coat of Arms is superior to Door of Destinies.

Good luck with everything and let me know if you make any changes that work!

Hexcimal

Thanks for all the suggestions, I really appreciate it! I will keep most of your suggestios in mind and give Anointed Procession another shot (was in the deck but had to be cut because I didn't have enough space. However, I do disagree on Coat of Arms and Door of Destinies. Coat of Arms is vulnerable to board wipe while if you get wiped with Door of Destinies your creatures can still come out with all benefits.

Again, thanks for the suggestions!

If you want to be extra gross and feel like you're cheating... try Reconnaissance. This card allows you to be hyper agressive and attack all-out while avoiding any unfavorable blocks (this is the 'fair' use).

This card also allows you to untap any first stike vampires like Edgar Markov or Drana, Liberator of Malakir after first strike damage is dealt but before normal combat damage is dealt. (handy for getting +1+1 counters from Drana to your whole team)... obviously busted with Stromkirk Captain. This card also allows you to untap after normal combat damage is dealt for pseudo vigilance as the creature is considered an 'attacking creature' all the way until the end of combat stage.

Anyways, here's my decklist... feel free to leave feedback or suggesions. http://tappedout.net/mtg-decks/edgars-dega-vampires/

Last_Laugh, I knew it was only a matter of time before you found my deck. :P I already saw the same suggestion given to Triton. Honestly, I can see why Reconnaissance would be a good card. However, I don't think it's necessarily needed in this deck.

Thanks for the suggestion!

Yeah I'm being a dirty whore and posting that same suggestion because it's excellent here and often overlooked. I'm hoping to garner some attention for my own deck because I can't seem to get people to post anything on any of my other decklists so I figured 'cross promotion' was worth a shot. Can't hurt and I'm being helpful so win/win.

The only problem is that the link doesn't work

A very nice deck, I have something similar in development. While playing I have noticed that Bloodsworn Steward is not that useful. If you can find something more interesting to replace it, I would recommend it.

hgjlesv

Once Ixalan is fully spoiled and/or released then I will have some more vampires to work with. ;P

Have you seen the vampires we've gotten so far in Ixalan? They're quite good, and I think they'll be super easy includes in the deck.

Only suggestion is the land base, I'd recommend at least the check/painlands since they're all relatively cheap and really help the deck. Kabira Crossroads is a land that really had me frowning upon when I was making changes haha.

I'll think of more suggestions, since I'm planning on motoring soon but I'll make sure to upvote your deck, being a fellow Edgar enthusiast as you know. ;)

Hope these suggestions helped!

Triton

I have seen some of the new vampires from Ixalan, and I do agree that they are pretty good. I'm just waiting for a few more to be spoiled before I make any decisions.

You will have to elaborate on check/pain lands though. (check lands are the ones like Glacial Fortress right?) I haven't been playing magic very long.

Thanks for the suggestions!

Correct, those are checklands. Painlands are Caves of Koilos and the other 9 2 color combinations and lands like City of Brass and Mana Confluence.