Hell's Park Underside/Sanzu River Area/Dark

Combat stats use the screenshot’s level, STR, MAG and VIT with the base stat formulas. Enemy skill bonuses are not included. HP is the recorded maximum.

Sources

Recommended demons

Follow the selected challenge’s roster/archetype rules. Special bonuses require the matching Underside skill, not merely the same demon name. Kill Nidhoggr first, Chatterskulls next and Ixtab last. Keep Evade Mortal active; uncontrolled area follow-ups can cause a wipe.

Earlier recommended alternatives

Queen MabBanner exclusive

Secondary weakness option

The guide identifies Elec damage for Nidhoggr’s weakness. Check roster rules and avoid accidental premature kills of the other enemies.

Earlier recommended alternatives

MephistoBanner exclusive

Banner: controlled Dark damage

Use the signature single-target Dark attack to remove Nidhoggr before the skulls, then finish Ixtab last. This avoids choosing an uncontrolled area carry for a strict kill-order fight.

Needs: Build the appropriate attack stat and MP; retain the guide’s Evade Mortal provider. Banner option for unrestricted clears only; not legal for a fusible-only or 4★-only challenge.

Watch for: Check every automatic follow-up in the whole team. Revive sealing, mitigation and Null Mortal do not let you ignore Ixtab’s fixed-damage death trigger.

Earlier recommended alternatives

Shiki-OujiAlternative

Area-specific Mortal protection

The matching Underside skill recasts Evade Mortal at turn start, with its stated battle limit. Keep the demon alive and refresh protection when needed.

Earlier recommended alternatives

Jack FrostAlternative

Controlled elemental alternative

With Jack Frost (Underside), use a single-target Dark transfer. Avoid area chain variants that kill Ixtab early.

Kit-based options; tested clears remain in the guide’s team section.

Skills on multiple demons:

Phys Pierce [weak] Underside

Used by: Chatterskull, Nidhoggr

Gains Phys Pierce. Damage received by enemy through this skill is reduced by 70% if the enemy has Null, Repel or Drain Phys attribute.

Source

Dark Pierce [weak] Underside

Used by: Chatterskull, Ixtab

Gains Dark Pierce. Damage received by enemy through this skill is reduced by 70% if the enemy has Null, Repel or Drain Dark attribute.

Source

Hell Recovery

Used by: Chatterskull, Ixtab, Nidhoggr

Adds Null Bind/MortaI. +80% to hit rate. +300 to Phys ATK and Mag ATK. +300% to status ailment auto recovery rate.

Source

Hell Ultra Booster

Used by: Chatterskull, Nidhoggr

+20% to Max HP. +100 to Phys ATK and Mag ATK. +25% to damage dealt. +100% to Healing skill effectiveness.

Source

Hellsent: Phys

Used by: Chatterskull, Nidhoggr

+40% to Max HP.. +100 to Phys ATK and Mag ATK.

Activates the following Chain Effect at the start of every second turn of the skill holder: Inflicts high-accuracy Phys damage (Physical, Power: 200) with a Bulwark-piercing effect and a 100% critical hit rate on all enemies.

Source

Hellsent: Dark

Used by: Chatterskull

+40% to Max HP.. +100 to Phys ATK and Mag ATK.

Activates the following Chain Effect at the start of every second turn of the skill holder: Inflicts high-accuracy Dark damage (Physical, Power: 200) with a Bulwark-piercing effect and a 100% critical hit rate on all enemies.

Source

Skills on Chatterskulls only:

Vengeance Blow

Used by: Chatterskull

Activates the following Chain Effect when downed during the enemy turn: Inflict Almighty (Power: 150) damage to the attacker, with 100% chance to inflict Mortal. Nullifies all death prevention skills. Won't activate when your party is wiped out.

Source

Skills on Ixtab only:

Yaxche [Underside]

Used by: Ixtab

Activates the following Chain Effect when the skill holder is downed: Inflicts 10,000 damage with a Bulwark-piercing effect 4 times to all enemies, with a 100% chance to inflict Mortal while ignoring all death prevention skills. However, this effect will not activate if the party is wiped out.

Source

Hell Mega Booster

Used by: Ixtab

+30% to Max HP. +200 to Phys ATK and Mag ATK. +50% to damage dealt. +200% to Healing skill effectiveness.

Source

Hellbound: Dark

Used by: Ixtab

+50% to Max HP.. +200 to Phys ATK and Mag ATK.

Activates the following Chain Effect at the start of enemy turn: Place 5 counts of Spirit Chains of Suppression on all enemies. (Once per battle)

Activates the following Chain Effect at the start of every third turn of the skill holder: Inflicts high-accuracy Dark damage (Physical, Power: 300) with a Bulwark-piercing effect and a 100% critical hit rate on all enemies.

Source

Skills on Nidhoggr only:

Nastrond [Underside]

Used by: Nidhoggr

Activates the following Chain Effect when an ally is downed: Restores 80% HP to the skill holder, then grants the skill holder a Bulwark with 20% of their HP. (1 turn)

Activates the following Chain Effect at the end of enemy turn: Revives a random downed ally with 100% HP.

Source

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.

Shiki-Ouji (Underside) effect overview

• 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.

Colors

• 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.

Skill Transfer

• Hell Gaze is ideal, otherwise Mudodyne works as a cheaper option.
• His innate Mudo can be leveled cheaply by transferring it from 1-2★.
• Null Dark grants him 70% damage reduction, to help him survive Ixtab's AoEs.

Brands

• MATK% Spell
• Due to his MP discount, Divine's MP regen is probably not necessary.

Misc notes

• He also has a 150% healing boost, but it isn't very helpful in practice. Stick with your healing items.
• He must be alive at the start of a turn in order to grant Evade Mortal.

Jack Frost (Underside) effect overview

• 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.

Colors

• (Any)

Skill Transfer

• 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.
  • Hell Gaze (Underside) starts at 7 MP, then becomes 6 MP at max level. This is the strongest skill he can use, but the cost of maxing it is very high.
  • However, using Hell Gaze (Underside) is risky, as its AOE might kill the Chatterskulls before Nidhoggr. Due to this, a single-target attack such as Mudodyne is preferred for consistency.

Brands

• MATK% Spell or Divine.

Misc notes

• If using Hell Gaze (Underside), then Concentrate only affects the initial hit, not the AoE chain.
• Consider transcending him for skill switches, as that lets him easily swap builds between multiple areas.

Team restrictions:

Difficulty	Restriction
Lv 3-5	3 or more demons must be fusible*.
Lv 6-8	4 or more demons must be fusible.
Lv 9+	All 5 demons must be fusible.
Lv 6+	1 or more demons must be grade 79 (4★ base) or lower.
Lv 9+	1 or more demons must be Clear .

Notes regarding fusibles:

• Multi-fusions count.
  • Beelzebub☆ counts, despite needing a gacha-exclusive material to make him.
  • For limited-time multi-fusions, only the ones that are currently-available will count.
• Pixie and Slime count, even though you cannot fuse them.

Sample party

Shiki-Ouji Skills Shiki-Ouji (Underside) Hell Gaze Brands MATK% Spell Requirements -

Indrajit Skills Elec Amp Elec Boost Brands MATK% Divine or Spell Requirements -

Izanami Skills Hell Gaze Maziodyne Brands MATK% Divine or Spell Requirements -

Anat Skills Serial Killer Elec Boost Brands MATK% Divine or Spell Requirements -

Anubis Skills Back Attack Assassin Brands MATK% Divine or Spell Requirements -

Team notes:

• Indrajit provides ATK Buff and single-target Elec damage.
• Izanami: 226 magic, has Merciless Blow and up to 35% Elec/Dark damage for herself (10% at p0, 35% at p4), another 20% Elec/Dark damage for party (10% at p0, 20% at p3), and -1 MP cost for the party's Elec/Dark skills at p4.
  • We're running both Maziodyne and Hell Gaze so she can switch to Hell Gaze once Ixtab is alone.
• Anat: AoE Elec damage with Thunderstorm, which also applies ATK Debuff, DEF Debuff, and Concentrate. If panel 2, also gives a 10% Elec damage aura and -1 MP cost of Elec skills for the team.
• Anubis: 217 magic, has Dark Boost, p3 has 10% damage, Purple has Merciless Blow. Mudodyne (160 power single-target).

Other options worth considering:

• Lucifuge: 206 magic, has Dark Amp. Light Devourer (170 power single-target). P3 also has a 10% damage boost, however it is ridiculously expensive to unlock it.
• Titania: 235 magic, Purple has Back Attack. Transfer Mudodyne (160 power single-target) + Dark Boost.
• Tsukuyomi: 216 magic, P3 has 5% damage. Red has Mudoon (140 power single). He's weak to Phys, so he needs a Resist Phys transfer to cover it.
• Black Frost: 201 magic, p1 has 15% AoE damage. If the enemy is Cursed, gets another 15% damage boost, plus the party gets another 15% (p3). Go to Hell! (110 power AoE).
• Lilith: 190 magic, p1 has 15% Dark damage. Allure (110 power AoE).
• Azrael: 194 magic, p3 has 10% Dark damage. Mudodyne (160 power single-target).
• Beelzebub: 184 magic (p1). Gluttony (130 power AoE), Mudodyne (160 power single-target).
• Pazuzu: 192 magic. Mamudodyne (120 power AoE).
• Rangda: 174 magic, p3 has 5% damage boost. Mudodyne (160 power single-target).
• Kudlak: 163 magic, p3 has 8% Dark damage. If the enemy is Cursed, gets another 15% damage boost. Mudodyne (160 power single-target).
• Skadi: 206 magic. Mamudoon (100 power AoE).

Team restrictions:

Sample party

Shiki-Ouji Skills Shiki-Ouji (Underside) Hell Gaze Brands MATK% Divine or Spell Requirements -

Mephisto Skills Dark Enhancement Dark Boost Brands MATK% Divine or Spell Requirements -

Lucifuge Skills Dark Boost Back Attack Brands MATK% Divine or Spell Requirements -

Hecate Skills Dark Amp Dark Boost Brands MATK% Divine or Spell Requirements -

Samyaza Skills Merciless Blow Master Assassin Brands MATK% Divine or Spell Requirements -

Team notes:

• If you don't have Shiki-Ouji, put Tetraja on your fastest unit, so you can cast it ASAP.
• Mephisto: 243 magic, has 25% Dark damage and Epitome of Wisdom 2. P1 has 15%, P3 has 20%. Purple has Dark Vital. Soul Levy (300 power single-target). Also has Drain Dark for the 70% reduction.
  • Yellow is also good for the buffs from Auto-Luster Candy.
• Lucifuge: 206 magic, has Dark Amp. Light Devourer (170 power single-target). Also has Drain Dark for the 70% reduction.
  • Gives a 10% damage aura to Tyrants, and can be upgraded to 20% at P3. Aside from Shiki-Ouji, everyone in this sample team is a Tyrant, so they benefit from this bonus.
• Hecate: 201 magic, P3 has 20% Dark damage. Purple has Dark Enhancement. Hell's Trivia (140 power single-target + 80 power AoE). Also has Repel Dark for the 70% reduction.
• Samyaza: 202 magic, has 20% Elec/Force damage, another 10% from Thunderforce levels. P1 has 15%, P3 has 20%. Purple has Master Assassin (the sample team's Samyaza is Red, and uses Master Assassin as a transfer instead). Thunder Reign (180 power single-target). Also decreases the team's magic skill costs by 1 MP, which is very helpful for demons that are MP-hungry. Also has Null Dark for the 70% reduction.
  • He's here for the battery effect, and to assassinate Nidhoggr as fast as possible. The Tyrant damage boost is also a nice bonus.

Other options worth considering:

• Beelzebub (Human): 193 magic, P3 has 20% Elec/Dark damage. Great Chaos (160 power Dark single-target + 80 power Elec AoE). Also has Repel Dark for the 70% reduction.
• Tezcatlipoca: 201 magic, has Dark Amp. Yohuallipoca (120 power AoE + 150 power random). Also has Repel Dark for the 70% reduction.
  • The AoE and random component have a chance to kill a Chatterskull too early and mess you up, so transferring Hell Gaze (or using him in Red ) might be a good idea.
• Beelzebub☆ (the 5★ one): 220 magic, has Butcher. Can automatically set up ATK Buff and DEF Debuff. Also has Repel for the 70% reduction. Will need a transferred attack skill.
• Loki: 198 magic, P3 has 5% damage. Clear has discounted Ziodyne (160 power single-target).
• Baphomet: 196 magic. Red comes with discounted Mudodyne (160 power single-target). Also has Null Dark for the 70% reduction.
  • Alternatively, Purple comes with Dark Boost if you'd rather use a different attack.
• Beelzebub (the 4★ one): 184 magic (p1). Gluttony (130 power AoE), Mudodyne (160 power single-target), Mazionga (100 power AoE). Also has Null Dark for the 70% reduction. May have MP problems, however.
• Pazuzu: 192 magic. Red has discounted Mamudodyne (120 power AoE). Also has Null Dark for the 70% reduction.
• Mishaguji: 183 magic, has Elec Boost, P1 has 5% Elec damage. Mazionga (100 power AoE). Also has Null Dark for the 70% reduction.
• Ikusa: 125 magic. Clear has Merciless Blow. Mamudoon (100 power AoE).

Team restrictions:

Sample party

Shiki-Ouji Skills Shiki-Ouji (Underside) Hell Gaze Brands MATK% Spell Requirements -

Guedhe Skills Dark Survivor Dark Boost Brands MATK% Divine or Spell Requirements -

Hecate Skills Dark Amp Dark Boost Brands MATK% Divine or Spell Requirements -

Cernunnos Skills Dark Boost Back Attack Brands MATK% Divine or Spell Requirements -

Anubis Skills Back Attack Mamudodyne Brands MATK% Divine or Spell Requirements -

Team notes:

• Anubis: 217 magic, has Dark Boost, p3 has 10% damage, Purple has Merciless Blow. Mudodyne (160 power single-target).

Other options worth considering:

• Lilith A:
• Baphomet:
• Murmur:
• Tezcatlipoca:
• Ame no Futotama:
• Lamia:
• Titania: 235 magic, Purple has Back Attack. Transfer Mudodyne (160 power single-target) + Dark Boost.
• Tsukuyomi: 216 magic, P3 has 5% damage. Red has Mudoon (140 power single). He's weak to Phys, so he needs a Resist Phys transfer to cover it.
• Black Frost: 201 magic, p1 has 15% AoE damage. If the enemy is Cursed, gets another 15% damage boost, plus the party gets another 15% (p3). Go to Hell! (110 power AoE).
• Lilith: 190 magic, p1 has 15% Dark damage. Allure (110 power AoE).
• Azrael: 194 magic, p3 has 10% Dark damage. Mudodyne (160 power single-target).
• Beelzebub: 184 magic (p1). Gluttony (130 power AoE), Mudodyne (160 power single-target).
• Pazuzu: 192 magic. Mamudodyne (120 power AoE).
• Rangda: 174 magic, p3 has 5% damage boost. Mudodyne (160 power single-target).
• Kudlak: 163 magic, p3 has 8% Dark damage. If the enemy is Cursed, gets another 15% damage boost. Mudodyne (160 power single-target).
• Skadi: 206 magic. Mamudoon (100 power AoE).