I'm sharing my notes on the strategy for the version of the Hyakki battle that is said to be impossible to conquer without a hack.
(This is translated by Deepl from the Japanese text, so the notation may be different and difficult to understand)
Here is the strategy
Continued with immunity 83 times, received a bailout, freed all physical ability items, freed all magic except Cool Calm, Frozen, and Silph Trick.
Since “El Period” is the mainstay of the game, releasing all offensive magic is a must.
Mainly uses Silfstorm, Hellbreak, and Rising (Cool Calm is a prerequisite magic and is released but never used).
Equipment (*important)
Weapon: Hellsize
Auxiliary: Scale Shield
Ornaments: Parasitic Juice*1
This battle strategy does not create edge daggers.
The author thinks that the most troublesome thing about the Hyakki battle is that the “Fear” anomaly is given.
If you get hit by an evil eye while you are under this, you will be in a lot of trouble.
Therefore, I equip Helsize with fear disable to prevent it.
In this case, the firepower is very poor, and melee attacks can only do about 20 damage. So, use El Period.
(Even if you use it, it will only do about 80, so it will be a more prolonged battle)
1About ornaments, the firepower of El Period does not change that much even if you use a skull cloak, and you can manage without using cream to reduce it, so I use the juice with a drastically reduced ecstasy probability for a reliable effect.
Choice of action
In the first turn, as long as the physical ability is raised to the maximum, it should have been able to get ahead without being debuffed, so buffs are applied in the following order
(Defense) → Rising → Silfstorm → Hellbreak
but to be honest, this is where you have to play the luckiest game of all.
I honestly can't decide which to apply first, the Silfstorm or the Rising, but I think that the probability of a magic being fired repeatedly is higher, so I think that the Rising is a good first move.
After that, shoot el period until the buff wears off (I'm not sure if it would be faster or not if I hot-limit it at this point).
Next, as for the choice of action during the transition of forms
I would go with a strategy that takes advantage of the fact that the Hyakki will always be ahead of you.
The specifications of the defensive stance are that it “always precedes and is not released until the next action is taken”, so when shifting form
Defend -> Rising -> Defend -> Silfstorm
I think it will be very stable if you put a defense between each action.
Also, the debuff of attack power is too slow to wait for natural recovery, so use Hot Limit to counteract it when you are done buffing it.
Hyakki doesn't have unlimited energy, so if you shoot magic several times, you'll get a lot of damage.
If you shoot magic several times, he will only do “spinning kick, evil eye, and breath.
In this case, it is no longer necessary to apply Rising, and you can get by with Hell Break to maintain your energy.
Even in this state, you still have to do the same thing.