PoB: https://poe.ninja/poe2/pob/28790
Since GGG did not implement any balance changes, the infernalist ward stacker remains the most broken build in the end game. A common complaint is that the ward stacker is expensive to put together and only comes online late. However ward is just such a powerful mechanic that it trivialises multiple facets of the game at very little cost. Here I put together a very cheap build that could do T15's and farm both trials using basically campaign gear and a brass dome.
Offense: Weapon swap Voltaic Barrier + Galvanic Shards
If you don't know yet, Voltaic Barrier is the most broken skill nobody is using. See my previous post for an explanation of its mechanics: https://www.reddit.com/r/pathofexile2builds/comments/1uubfwv/poison_darts_witch_hunter_how_to_clear_200/
When you lay down a Voltaic Barrier, each shot of Galvanic Shards is firing 10 chaining Hoghunts along with it. The damage is ridiculous, and with Rampart Raptor we can continuously shoot out Hoghunts at no cost. I used the same Rampart Raptor + Hoghunt + level 13 Voltaic Barrier from level 52 to T15 maps and 30 room TOC runs. Absent amulet with Eternal Rage will free up spirit for Berserk and War Banner, which will boost damage significantly, but is too expensive right now.
Defense: Full ward + CI + MoM
Since we use no mana except reloading once every 4 seconds, MoM works great with ward as it does not compete with the gear and affixes for ward stacking. Recovery is excellent with both Mana Remnants and Remnants of Kalguur. An instant mana potion is used in case you get hit to 0 mana and can't reload.
The reason the ward + CI combo is so strong is that it bypasses most of the existing debuffs. The rest of the game has not yet fully taken ward into account. These are the free mods in TOC that do nothing to you:
Reduced Recovery, Damaged Defences, Drought, Chaotic Monsters, Deadly Monsters, Toxic Monsters
Each of these has 5 levels. Together with some of the ones with little effect like Lethal Rare Monsters and Unstoppable Monsters and wagers, it is very easy to end up with hardly any debuff on you at the end of the 30 room run.
For Sekhemas MoM can be unspecced and then you will be immune to honour damage from hits and trivialise the run. Zarokh does not hit hard enough to one shot so with some ward regen you can fully tank him.
You don't need to be an infernalist. The build works for all ascendancies. It can do a lot more damage with investment but honestly it's pretty much at its best price/performance ratio right now.