POB: https://pobb.in/LUwQrNLkKc1g

Mechanics

The new Heroic Tragedy timeless jewel converts notables and keystones in radius to ward related ones. The Celestial Mathematics keystone (Uhtred variant) gives you 25% of your ward as added cold damage, in exchange for breaking your ward on Attack.

However, the keystone can also convert some notables to Regenerative Runes, which gives you 2 flask charges when your ward breaks. If you get enough of these (I have 4) and enough increased flask charges gained / reduced used, you can get an Iron flask (restores ward on use) to permanently restore your ward.

The cycle is: Attack (or get attacked) -> Ward breaks -> Gain flask charges -> Iron flask gets filled (enchanted with used when charges reach full) -> Ward restored -> Repeat

Now we can just stack ward with Ynda's stand and some ward gear. With my current setup, I have 17,500 ward. This gives 4375 added cold damage to attacks, and basically immunity to any hit that does less than that.

There's also some nice benefits that come with this, such as gain X charge when ward is broken (which is whenever we attack or get hit), remove a damaging ailment whenever ward is restored, recover 4% of life when you use a flask, etc.

I'm definitely not the first one to discover or share this, poopbutts has a great video here: https://www.youtube.com/watch?v=LQd4NduWqP8, and there was a great theorycrafting thread here: https://www.reddit.com/r/PathOfExileBuilds/comments/1rqqbna/theorycraft_immortal_afk_wardlooper_in_league/

I just managed to get a 4 Regenerative Runes and Ynda's before the prices skyrocketed.

"Showcase"

In quotes because the build is still quite scuffed (level 93, not max level gems, 0% quality on everything, etc). There is definitely a lot to improve in the build, but I'm happy with where it ended up, and it farmed enough currency for me to try some other builds.

I think this archetype has crazy potential if you can manage to get it going.

Uber Exarch: https://youtu.be/pPSzOncgaOE

Uber Eater: https://youtu.be/8jJKQblMX2Y

Mapping (and a little tank test at the end): https://youtu.be/JJZRjFfgl90