I don’t think Voidsoul Flames of Ignaffar (FoI) is very popular since it has very attractive doom bolt and aegis bonuses, so I want to share a set up that can facetank Callagadra without crystal or pharma: Purifier, Level 100 (GD 1.1.9.6) - Grim Dawn Build Calculator ; while specializing a build to do a single boss is probably not very impressive but since this likely gonna be my only build who can achieve this feat I felt like posting this.
Resists are poor because we need overcapped pierce res for Callagadra; otherwise we could roll with this: Purifier, Level 100 (GD 1.1.9.6) - Grim Dawn Build Calculator
Callagadra fight
Had to dash around the boss a few times because otherwise I couldn’t put Inquisitor seal on myself when it’s directly below me. Could have rotated the camera instead, but that’s a big no from me when playing an isometric game.
My charsheet showed 198K damage on FoI. This seems pretty good considering it’s honest (compared to fire/cold/elemental FoI setups which has slightly higher numbers but 50% of it is DoT).
No Tainted Flame
With perfectly rolled conversion value on Voidsoul helm/chest and the conduit amulet, we have 101% elemental damage converted to chaos. This means we don’t need Tainted Flame for the conversion, although 15% more damage is still attractive. I did some manual calculation and (before % damage is applied) I had 899 average chaos damage per tick (1000 with abomination) after tainted flame is applied while without it I had 967 average chaos damage per tick (1075 with abomination) thanks to the converted lightning damage. This was verified in game - I had more chaos damage per hit with the transmuter removed.
Note that the total charsheet still showed tainted flame having slightly higher damage, but this is kinda a lie because it involves vitality damage which we don’t have resist pierce for (and vitality resist is higher on average on enemies - Callagadra has 134% vitality res so our vitality damage might as well be 0).
Constellation
I started out with a standard Dying God + Abomination set up but it couldn’t sustain FoI’s energy cost for the >2 minutes needed for the fight due to a lack of % energy regeneration. After swapping Abomination out for Lantern and Panther I had enough points for Korvaak, so I went all the way, but I was doing better with Abomination (I suppose mana regen pharma could have helped, but I felt like making a build without consumable).
Deceiver vs Purifier
For this fight Purifier is definitely better because we get all the relevant stats such as DA/speed/RR. We don’t have enough points and gear (especially the gloves slot) for Doom Bolt outside of this fight anyway.
Doable with realistic gears?
I don’t think so, “of the Dranghoul” green items are very much needed to fix the class combo’s otherwise pretty mediocre OA/DA. Edit: as pointed out by a post below I think “of Readiness” could make this feasible, although harder with the reduced armor.
Inquisitor Seal/Blast Shield vs Temper
This build invests in Temper because I wanted to have at least 3058 DA (less when Korvaak procs, but it doesn’t always proc) to avoid getting critted. Flat absorb from Blast Shield/Seal barely flinches the massive damage Calla can dish out (which are in the thousands). In Crucible it’s better to max Blast Shield.
The alternative to having 3058 DA is to get around 20K HP and a bit more leech, which is kinda a mountain of a task for Purifier.