I decided to polish this up but I can't guarantee I'll be able to do this for future previews as it's very time consuming and requires I get a full extra day to work on it.
I don't think I mentioned this in the mechanics but Ignite did not appear to contribute to his Death Mark bonus damage. I refer to this later in the video, though.
I'd also say that the Death Mark tracking only appeared to work for the duration of his normal dash (this is why I'm careful to say the duration of the animation). In other words, if you're still moving when the dash would normally finish, you'll still get further away from Zed.
Finally, he's not an outstanding chaser against fast targets, or while he is being slowed. If you don't kill a fast champion quickly they will rarely have an issue simply running away from you. This is part of why I recommend a phage at the very least.
These are all beta mechanics. A lot of them are likely to stay the same on release but always be aware of this.