Head off on expeditions or investigations to the Rotten Vale and while you’re there, search for blue tracks until you fill your research bar for the unknown monster - revealed as Vaal Hazak once your investigation is finished - and talk to the Third Fleet Master. The order doesn’t really matter, so long as you complete both of these objectives. Once done, be sure to Chief Ecologist and this quest should start.

Hunt - Vaal Hazak¶

There’s no element to defend yourself against this time, this new dragon, Vaal Hazak, deals in ailments, not elements, and aside from some luck with decoration drops, the only way to get gear that’ll protect you from the ailments it inflicts are by making armor from the materials Vaal Hazak itself drops. Since prevention probably isn’t possible, you’ll have to rely on curatives to counter the effects of the ailment. Bring plenty of Nulberries with you, and a variety of healing items, including max Potions. You should also check your decorations, as Miasma Jewels grant the Effluvia Resistance skill, which is what defends against - or outright blocks at rank three - the ailment in question. Even one will help, so if you have it, you might as well use it. Gobbler decorations (Speed Eater) may also help to recover from the effects of the ailment fast.

Vaal Hazak is weak to both Fire and Dragon, but resistant to Water. This should give you plenty of offensive options as far as weapons, go. It’s not particularly weak to any ailments, but if you must bring something, it’s more susceptible to Blast and Stun than anything else.

Travel to the Rotten Vale’s Central Camp, jump off two ledges to the north and east, then descend through two chambers filled with caustic water before turning northwest and passing through some diseased vines to reach Vaal Hazak’s grotesque lair. After it shows off its supernatural powers - and its position on the food chain (and on the gore hill) it’ll turn its attention to you.

Kushala Daora was a western-style dragon, Teostra resembled a Chinese guardian lion, and Vaal Hazak is… well, if it’s anything, it’s a dracolich. It doesn’t dabbling in elements, instead the deadly toxin of the Rotten Vale itself is its tool, to which it is bound in a symbiotic relationship. Would that make the effluvia that permeates the Rotten Vale bacterial? Whatever the case, it hurts you and empowers Vaal Hazak, who can concentrate the toxin in ways far deadlier than exposure to the toxin in other parts of the area.

Vaal Hazak has fewer attacks than Teostra, but like Kushala Daora, it’s shameless about spamming some of them. For close-range foes it has a lunging bite, a claw sweep, a spinning bite attack that can hit foes to the flank and rear, and a tail sweep - making it pretty capable of hitting foes that aren’t in front of it. Despite this, its frontal attacks are worse, so you’ll want to endeavor to stay to the side and rear, especially when it gives certain tells.

The movements of this Elder Dragon are somewhat odd, being relatively ponderous at times… at least compared to Nergigante, Kushala Daora and Teostra, but this apparent lethargy is often off-set by the range of its attacks and sudden bursts of speed. Showcasing this are its numerous charge attacks, which include a leaping attacks of various ranges, a multistage charge, and a proper sprint that covers a surprising distance.

Like Teostra, Vaal Hazak accumulates its favored, latent form of attack around - or in this case, within - itself, growing more dangerous the more it accumulates. As the fight drags on, Vaal Hazak will gather effluvia about itself, at the last stages of which will form a mist around the dragon that damages melee attackers. It’s a small amount of damage, but it can add up.

Much more dangerous are the ways that Vaal Hazak actively discharges effluvia. On the positive side, these attacks are all front-focused (albeit with an area of effect) and Vaal Hazak usually makes a point of rearing up and/or inhaling before releasing the attack, giving you plenty of time to react. On the negative sides, Vaal Hazak isn’t shy about using some of these attacks at quite a long range (perhaps preventing you from reaching the dragon’s flank, and hence, safety) these attacks cannot be blocked and must be dodged, and they tend to do massive damage. Of, plus there’s a high chance that they’ll afflict you with their health-sapping taint on top of all that, but more on that later.

These attacks include a long range stream of effluvia which Vaal Hazak will sweep back and forth - probably its most dangerous attack, due to the damage and frequency which with the dragon will use it, but if you’re safe when it starts the attack Vaal Hazak can’t turn during its lengthy duration, so there’s plenty of time to attack. Vaal Hazak can also expel a cloud of dense effluvia centered on itself, which will constantly drain the health of hunters who are caught inside. This effluvia cloud attack is often preceded by a roar, just to be more obnoxious. Finally, there’s a variant on the effluvia cloud where Vaal Hazak will vomit a gout of effluvia in front of it, affecting a relatively small area, but dealing heavy damage if it hits. This damage seems to scale with how much effluvia Vaal Hazak absorbs, which usually correlates with the duration of the fight (at least since the last time you stunned Vaal Hazak or otherwise interrupted its effluvia build-up), and can be diminished with Elderseal weapons.

Vaal Hazak’s attacks - usually its effluvia attacks, but by no means excluding its other attacks - can taint a stricken hunter. When effected, your health bar will drop to half its current size, which for all intents and purposes makes you a one hit kill from some of Vaal Hazak’s attacks. You can cure this affliction with a Nulberry, but it won’t restore your lost health, which must then be restored by other means. Obviously, this can take some time, leaving you quite vulnerable to being carted by follow-up attacks. Speed Eating will help considerably with this, but Max Potions serve in a pinch.

Attack the head, belly and tail to deal the most damage, although your mileage will vary depending on what you attack and what weapon type you’re using. Blunt damage is most effective on the head and least effective on the tail, Cut damage affects the tail the most, but deals decent damage to both the head and belly, while Ammo damage is most effective against the head and tail, and least effective on the belly. The head and belly are both breakable, while the tail is severable. It’s weak to Fire and Dragon damage and resistant to Water. It’s not weak to any ailments, but Blast and Stun should both find purchase.

After the battle with Vaal Hazak you’ll find yourself in Astera again, chatting with The Handler and the Admiral, who will tell you that his friend found what he was looking for - presumably the reason behind the Elder Dragon’s erratic behavior. The final battle awaits, and your presence is mandatory… which makes sense, considering your knack for handling Elder Dragons thus far. Talk to the Commander after this for some more chatter, followed finally by The Handler, after which you’ll be able to pick up the assignment Land of Convergence.

You’ll also ascend to Hunter Rank 15 - your final Hunter Rank increase before the end of the main questline, in fact. You’re close to unraveling the mystery behind the Elder Crossing, just one more assignment to go!