Disclaimer: Mageblood + Original Sin build. Literally not playable without Original Sin, and multitudes weaker without Mageblood.

PoB: https://pobb.in/vGW4h_AQIwDV

Winter Orb is generally known for its S+ tier clear but lackluster duration and single target. With Original Sin, this opened up an opportunity for me to tackle these problems. I needed a build that trivialised Sanctum because I practically have no patience, and the autotargeting property of Winter Orb is perfect for the job so it was great timing.

One of the best ways to scale duration is to play a DoT build. Many DoT nodes on the tree come with duration and so does Malevolence which is huge QoL for many things. My Winter Orb for example, lasts almost 9 seconds if I fully channelled it to 12 stages, and for mapping purposes I channel it to 5~ or so stages and barely have to recast it, which in comparison to hit-based variants is night and day. Obviously to do this you would either have to play an ignite or poison build; ignite isn't very good as Winter Orb is a high frequency, low impact hitting skill so the ignite would be insignificant, but it's fine for poison given Original Sin's release. Personally I have a huge dislike for channelled abilities unless you have major stationary defences, so not having to channel so often was a huge plus.

Additionally, Winter Orb has notoriously struggled really hard to deal decent single target without charge stacking and an Ice Bite Forbidden Shako. Obviously, like Blade Vortex, most people play this skill for mapping purposes, but I wanted to see if I could make it deal reasonable uber boss dps, and I ended up pleasantly surprised as I could hit the DoT cap within 9~ poisons which is fairly trivial for Winter Orb due to its high hit rate.

Most of this damage scaling comes from being able to use both Elemental Overload and Hatred for significant more multipliers, something most poison builds don't have the luxury to do so (even Spark can't use Wrath as it specifies spell lightning damage, but Hatred is generic cold damage). This is on top of being an Occultist letting me pick up both Frigid Wake and Withering Presence, and using FF jewels for Heart of Destruction. To get Wither, I use a Glorious Vanity instead of a Balance of Terror because I don't like to stop to cast Despair every 10 seconds, and I also needed Corrupted Soul to have enough ES for Eldritch Battery anyway.

Overall, I ended up with a very smooth and low effort build that has great clear due to double explode from Asenath's and Profane Bloom, do all map mods (less recovery is the worst because my EB recharge becomes slow) and also deals reasonable uber boss dps. Sadly the defences are lackluster (I will die to 1 Uber Exarch ball), and while I'm sure there's probably a way to make this build significantly tankier without compromising much, I didn't put much thought into it because defences are pointless in Sanctum.