How to access:
Clear all of the Lost Chapter stages in Normal mode (no need to get a full Complete on everything at first) to unlock their Hard versions. This will give you access to the Hard (CHAOS) version of the last boss fight.
Stage Difficulty: Level 180 (CHAOS)
Mission Requirements:
Score 710k | Clear without any KOs | Clear within 90 turns | Take 20000 or less HP damage
Boosted Characters: Prompto, Freya, King
Many team ideas with and without boosted characters are available in this event’s Call to Arms!
Fight Overview
This is a rather easy fight if you have been keeping your roster updated with some recent units; if not, the biggest hurdle will be the tight turn count. Luckily it is a rather short fight, so don’t be afraid to try out different character combinations if you fail at first.
Recommended:
- Strong melee or ranged group damage dealers, or attackers with lots of free turns from their skills;
- A strong tank, or at least a support who can battery the party to avoid breaks. Snow or Warrior of Light make the fight a cakewalk, as does Porom. Zack is gimped by the magic nature of his EX, but could work if paired with Lenna, to avoid the Curse debuff. Galuf works well in the second wave, but suffers in the first one that is mostly magic attacks. Celes has the same problem in reverse.
- Debuff avoiders like Lenna/Selphie/Ignis, or debuff cleansers like Yuna, to avoid the Curse and Confuse debuffs;
- Healers or damage mitigators to deal with the unavoidable HP damage in the last wave;
- Debuffers can have a field day, because the enemies have no debuff resistance at all;
- Dispellers are not necessary, but are helpful in the last wave with their penchant for buffing themselves.
Avoid:
- Characters with
Magic attacks. They will get countered in the first wave and deal 90% less damage in the second. - Characters with
or 
attacks, as the Imps absorb those elements.
Summon options:
- Leviathan, Brothers and Diabolos are good summon options (choose the one appropriate to your team).
- Ramuh and Pandemonium are not recommended, due to the elemental absorption.
Wave 1: Astaroth x2
| Magic Slug |   attack;“+” version: triggers Drain when inflicting Break or attacking target afflicted with Break |
| HP Attack |  attack |
| Drain | Increases BRV when BRV less than INT BRV; attack; restores HP |
| Light of Sanctions | attack; fair chance of inflicting  5T Curse (halves MAX BRV and INT BRV) on target;“+” version: triggers Drain when inflicting Break or attacking target afflicted with Break |
| Wild Spear |  attack;inflicts 3T DEF Down on target;“+” version: triggers Drain when inflicting Break or attacking target afflicted with Break |
| Counter Light of Sanctions | Counters when hit by attacks; attack; inflicts 5T Curse (halves MAX BRV and INT BRV) on target |
Attack follows Break!: All skills become their “+” version, following up with a “Drain” HP attack (activates at 80% HP)
Revelation: Raises ATK, INT BRV, SPD (activates at 50% HP)
Enrage: No. They do not power up when the first one dies.
There are two simple rules for this wave:
1. Don’t use magic attacks
Any magic attack with a BRV hit (regardless of dealing HP damage or not) will be immediately countered with Light of Sanctions, which deals good damage and inflicts 5T Curse (halves MAX BRV and INT BRV). Needless to say how much that sucks.
2. Don’t get broken.
After reaching 80% HP, the Astaroth adds a follow-up Drain attack to its other skills whenever they Break or hit a Broken target. This can quickly become dangerous, as all of their moves will become BRV+HP attacks; so either bring a good tank or manage your BRV well to avoid being broken.
Other than that, they are fairly basic foes and all their attacks hit a single target, so your main concern is avoiding Breaks and the Curse debuff while not wasting too many turns oh them.
Wave 2: Sergeant Imp x2
| Rake | attack |
| Flying Kick | attack; |
| Confuse | attack; fair chance of inflicting 2T Confuse on target; |
| Critical | Guaranteed Critical attack |
| Evil Ration – Attack | grants  3T ATK Up, 3T MAX BRV Up to one ally;“+” version: also grants party BRV |
| Evil Ration – Defense | grants 3T DEF Up,  3T Shield to one ally;“+” version: also grants party BRV |
| Command Rush | attack; inflicts 3T SPD Down on target;high turn rate |
| Calamity Bomber | Recovers from Break;  attack + attack;Deals full HP damage to each target; inflicts 3T DEF Down on all targets; |
| Role Switch | Changes actions |
Moving furiously…: Raises ATK, DEF, SPD, INT BRV, MAX BRV (activates at 80% HP)
Glaring this way…: Raises ATK, DEF, SPD, INT BRV, MAX BRV further (activates at 50% HP)
Enrage: Yes. The remaining Imp will power up with “Glaring this way…” when the first one dies.
If you played during the first Prompto event, this is pretty much the same fight with increased stats. The Imps will keep buffing their attack and defense while hitting you with mostly Melee attacks.
Their most noteworthy buff is a 3T Shield, which acts exactly like Warrior of Light’s and will absorb a set amount of BRV damage before breaking. It can be annoying, especially if you find yourself needing to shave a high amount of BRV before a dangerous attack; but if you bring a good enough damage dealer from our most recent banners, this shield will melt like butter.
They apply some slightly debuffs, the worst of which is a 2T Confuse. The easiest way to deal with them is by having a tank (to focus all debuff attempts on them) or some debuff evasion like Lenna. Some teams can ignore them, as these debuffs are not as crippling as Curse, but beware that Confuse can put you in risky situations or waste precious turns on a fight that already has a tight turn count.
The big attack you need to watch for is Calamity Bomber. It is very predictable – the only attack in the fight – and since it is a group BRV + HP attack, it has the potential to deal very high damage, especially if it breaks someone in your team. It is the main reason this fight asks for a good healer or other ways to mitigate the incoming damage.