Simply what is needed to survive this boss fight.
Main Guide
Things you need for the fight:
- Stats: At least 1800 HP. Nightmare opens the fight with an immediate attack, which could kill you instantly (vigor check!)
- Weapon: Life Staff (starting staff, life path, preferably Stage 4), which you need for the special skill: Life Fruit
- Spells: 6 or 7-Pillar Ice with Advanced Focus Circle (they both do about the same amount of damage)
- Ice will keep Nightmare’s agility low, meaning he will have far less turns between yours
- Pets:
- Seed Spirit: Keeps your MP high, combined with the cheaper ice spells
- Lucca: Gives you extra turns (free agility)
- Nekomis or Tia Rion: This covers you for keeping the ice debuff on, in case you need to do something other than cast ice (like cast Life Fruit)
- Do not summon Justice, even though he is free. His fire attack will remove the ice debuff, allowing Nightmare to suddenly and unexpectedly attack
- Armor: You will probably already have the best armor by this point
- Consumable Items: The very occasional MP potion. Only needed after some of Nightmare’s attacks, which drain MP.
That’s it, now it’s just a battle of attrition, except you will win. Keep the ice debuff up, and cast Life Fruit whenever it’s available. You will have tons of turns versus Nightmare, and you will have a massive health pool built up from Life Fruit (as high as 7000) which will mitigate any high damage attack when it arrives. You probably want to defend when your total health pool is below 4000 and Nightmare is going to attack soon after your turn, otherwise just attack because you can tank his upcoming attack now.
Thanks to cro for his great guide, all credit to his effort. you can also read the original guide fromĀ Steam Community. enjoy the game.