What ballpark range do you need to be to take Shadow Empress down

Server lag doesn't add 20 seconds.
A simple pause to check if DR is up after 65 seconds would be fine, 20 seconds is way overkill.

I don't know what this refers to, DR is 20 secs which can be +/- 2-3 secs due to server lag. DR CD NEVER changes, so if you use something like 65 secs, you can end up stopping for DR at 85 secs instead of 80 and still kill yourself. Obviously, if you really want to survive, you stop to check beforehand but I'd be stopping too late if I used 65. If you used any of the thieves exception of Phantoms, they're a perfect example of how to screw yourself over if you rely on that icon too much instead of actually timing that DR down. Of course, as a DB I always check DR with CoH regardless, but that's not the point. Server lags and skills like venom will almost definitely screw your DR timing down if you rely on icon alone.