Hell's Park Underside/Sanzu River Area/Dark

Sanzu River Area (weak to Dark)

Overview

Chatterskull	Ixtab	Nidhoggr	Chatterskull

Skills on multiple demons:

Skills on Chatterskulls only:

Skills on Ixtab only:

Skills on Nidhoggr only:

Explanation

Hellbound: Dark will apply 5 stacks of Spirit Chains of Suppression to you.
Vengeance Blow - When a Chatterskull is killed, it will cast an Almighty hit with Mortal on their attacker.
Nastrond Underside - When an enemy dies, Nidhoggr gets a full heal and a 20% HP Bulwark. When your turn ends, a random enemy gets revived at 100% HP.
Yache Underside - When Ixtab is killed, she will deal 4 AoE hits of 10,000 fixed damage + Mortal, which also pierce Bulwarks and ignore endures. The gist is that she will wipe your party unless she dies last.
If the adds are not dead at the start of their second turn, they will hit you with a bulwark-piercing, 100%-crit enrage AoE. Ixtab will do one too, if she isn't dead by her third turn.

Set up Evade Mortal (with Tetraja, for example) as soon as possible, and refresh it when it runs out. Make sure it's active to shield the revenge Mortal hit whenever you kill a Chatterskull.
- If you bring Shiki-Ouji with the skill Shiki-Ouji (Underside), then she will automatically cast Evade Mortal at the start of your turn.
Focus on killing Nidhoggr first (preferably with single-target attacks), then kill the Chatterskulls, and kill Ixtab last.
- If Nidhoggr does not die first, then he will get a full heal and a 20% HP bulwark when each of the Chatterskulls die.
- If Ixtab is not killed last, then you will wipe.
- Do not simply AoE everything down with Dark! - if you try that, then the skulls will die first, Nidhoggr will heal + bulwark, then Ixtab will die, leaving Nidhoggr still alive, and you will wipe.
- Nidhoggr is also weak to Elec, and nobody NDR's it. Therefore, Elec AoE units can heavily damage Nidhoggr while only lightly damaging the other enemies.
Try to cover your Dark weaknesses, as Ixtab will spam Dark AoEs during her turn.

Self gets 50% HP, 180% Dark damage, 20% accuracy, 3 MP discount for Dark skills, and immunity to Spirit Chains of Suppression.
The team gets 30% Dark damage and 30% accuracy.
At the start of your team's turn, your entire team gets Evade Mortal (up to 3 times per battle). This saves a Press Turn you would've needed to spend on casting Tetraja.

Clear for the fusibles ruleset. However, keep in mind that Lucifuge is a strong demon that can satisfy this requirement instead.
Yellow for Rakunda, if you need a source of DEF Debuff.
Purple for Back Attack, which is a 3% damage gain.

He also has a 150% healing boost, but it isn't very helpful in practice. Stick with your healing items.

Self gets Concentrate (2.25x damage) on his first action - this is about 63% damage on average across his 2 actions on the first turn. Also gets 50% HP and immunity to Spirit Chains of Suppression.

Use Mudodyne.
Jack Frost does not have any MP discounts, so 7 MP skills such as Hell Gaze may be too expensive to cast repeatedly.

Consider transcending him for skill switches, as that lets him easily swap builds between multiple areas.

Team restrictions:

Difficulty	Restriction
Lv 3-5	All 5 demons must be of the races Tyrant, Vile, Brute, Drake, or Night.
Lv 6-8	All 5 demons must be of the races Tyrant, Vile, Brute, or Drake.
Lv 9+	All 5 demons must be of the races Tyrant, Vile, or Brute.