So previously with the ht head glitch you only needed 7.6k hp to survive ht. With the introduction of the new source patch, which haven't been released they fix the issue with ht head, meaning it would deal 9k magic damage. I was informed that ht damage has already been changed to 9k damage as of today. So how much hp i would actually need to be able to ht as a nl.
Yes I've heard around 7.6-7.8k works too, but 9.1k is to ensure maximum safety. In case NL forgets to dark sight or they are attacking too close to the wing, and the wing hits them, there's a possibility of dying (then again, NL avoid is op too ). Wing can hit just over 9k iirc. It's fine to wash only up to 7.6-7.8k as well, as long as you avoid the wings at all costs.
They can HT with 5k or 6k only as you said due to dark sight. An example is beautician who only has 6k hp. But they end up dying on mass send e.e
@lobix10 I believe he has 8k now xD I guess you could technically do it with 5.6k as long as you don't fall down from head A too, but that would be very difficult. 9.1k as @Gurps said is the safest though