THQ Nordic and Gunfire Games have released a new gameplay trailer for Darksiders 3 titled Flame Hollow. Contrary to the first impression you might have, Flame Hollow doesn't refer to a place but rather one of Fury's forms as seen above.
THQ Nordic have previously stated that they don't want Fury to use gadgets like War and Death did in the previous two games, and instead focus on her wizardry. This trailer offers the first glimpse of that system, as the Flame Hollow form offers Fury apparent immunity to fire, different weapons and improved acrobatics.
Her immunity to fire is apparent when she is seen fighting a monster in a lava pit in the trailer and her traversal tool kit is expanded with a fiery jump that can help her reach otherwise inaccessible heights. Considering the first ability will let her cross fiery liquid insta-death and the second one will let her reach areas that don't have conveniently placed whip latches, it is easy to conclude that her forms will pull double duty for traversal and puzzle solving.
Her weapons also get altered in different Hollows apparently, as her whip is nowhere to be seen while in the Flame Hollow and she instead uses what resembles two flaming flails. It is also possible enemies will have different resistances and weaknesses so different elemental forms might help with specific combat scenarios as well.
This is speculation at this point though as the only two revealed forms so far are Fury's base form with the whip and Flame Hollow. There are still that remain secret, but they should be revealed soon enough as the game is just over four months from release, which should happen on 27 November 2018.
It may be worth noting that Fury is also seen using a greatsword in the trailer above, but this weapon doesn't seem to be tied to Flame Hollow. Greatswords are War's speciality and both him and Death have previously used weapons affiliated with their siblings Fury and Strife, so it's probably Fury's turn to take a family weapon for a spin.