[Standard] MTGArena: Improving on the Legion of Dusk (W/B Vampires) Deck

[MTGArenaRun]

Greetings,

A few months ago, I started making gameplay videos of MTGArena with the initial concept of how to build from a stock deck. I would take a deck and run it through Quick Constructed (single game matches, with prizes scaling per match win up to seven and elimination at three match losses) as is, then make adjustments to the deck after the run as a framework for improvement.

Now, with the release of Kaladesh and Aether Revolt on MTGArena, I made the following changes to accommodate the new meta and fill out a sideboard for Competitive Constructed (matches are best-of-three games with sideboard, with prizes scaling per match win up to five and elimination at two match losses), which is probably more representative of true competitive gameplay.

(The below deck has been adjusted to 3.0 after the Run. See post below to note changes.)
Display deck statistics

I detailed my thoughts on the deck in this video.

I'm currently midway through the Competitive Constructed run. Currently, I am 2-1, with wins against Mono-Red Aggro (complete with Goblin Chainwhirler and Rekindling Phoenix) and White-Blue Control (complete with Torrential Gearhulk and Teferi). It is the one loss that I am thinking over, and that has me wondering what I could take away from it.

The loss was to a fellow W/B Legion of Dusk deck, and it appears to be a stock deck with few tweaks, notably in the addition of Gifted Aetherborn. I originally ditched most of the high-cost five-drops (previous reasoning in this video) and figured that a streamlined early-aggro late control deck would be the way to go. Now, I am wondering if I should have taken the less aggressive approach and went with a mid-range deck... I figured I'd ask you guys first as I have been using the site to do all the number-crunching and analysis.

For reference, the match in question is the second match in this video.

[MTGArenaRun]

Finished the run with one more win and the final loss. Final standing is 3-2.

My initial conclusion is that the deck needs to be able to shift towards both extremes. The sideboard needs to make the deck more aggro on one end with more one-drops, then be able to make the deck more resilient in the end game with some choice big vampires. I may need to return one or two of the 5-drops I dismissed earlier.