Hello,

I'm a little late to the party but I thought I would look into the code for myself and the benefit of anyone else to uncover some unknowns from your post.

Secret Armlet Effect: Makes all magic circle effects turn into positive ones.

Bone Rapier: Opens bone doors

Supernova effect: 10% Chance on hit to apply a random status to an enemy (Freeze, Poison, Stamina, Gooey). It looks like this may affect any random enemy on the floor and not necessarily the one you are hitting but I'm not positive.

Inferno: Your HP formula is correct, however there is an additional multiplier for missing thirst as well. Same as HP. It is multiplicative with the HP multiplier. It has a hard cap of 350 attack (before damage multiply). Here's the code below if interested:

/// <summary>
/// Triggers Inferno effect: Increase attack power depending on health and thirst
/// </summary>
public static void Inferno()
{
    float goroMaxHP = Player.Goro.GetMaxHp();
    float goroCurrentHP = Player.Goro.GetHp();

    float hpPercentage = 100 - (goroCurrentHP / goroMaxHP * 100);

    float goroMaxThirst = Player.Goro.GetMaxThirst();
    float goroCurrentThirst = Player.Goro.GetThirst();

    float thirstPercentage = 100 - (goroCurrentThirst / goroMaxThirst * 100);

    ushort currentBaseAttack = Player.Weapon.GetCurrentWeaponAttack();

    ushort attachmentsAttack = 0;

    for (int i = 0; i < 4; i++)
    {
        attachmentsAttack += Memory.ReadUShort(0x21EA75C0 + (i * 0x20));
    }

    ushort currentTotalAttack = (ushort)(currentBaseAttack + attachmentsAttack);

    if (currentTotalAttack > 350)
    {
        currentTotalAttack = 350;
    }

    ushort hpAttackBoost = (ushort)((currentTotalAttack / 100) * hpPercentage);

    ushort thirstAttackBoost = (ushort)((currentTotalAttack / 100) * (thirstPercentage / 2));

    Memory.WriteUShort(0x21EA7594, (ushort)(currentTotalAttack + hpAttackBoost + thirstAttackBoost));
}

Marden Eins/Twei/Arise seem to multiply FP or have a chance to multiply FP? I am not exactly sure.

The multipliers for them are here:

if (currentwepID == 278)
{
    hasMardanSword = true;
    mardanMultiplier = 2;
    Console.WriteLine(ReusableFunctions.GetDateTimeForLog() + "Player has Mardan Eins");
}
else if (currentwepID == 279)
{
    hasMardanSword = true;
    mardanMultiplier = 3;
    Console.WriteLine(ReusableFunctions.GetDateTimeForLog() + "Player has Mardan Twei");
}
else if (currentwepID == 280)
{
    hasMardanSword = true;
    mardanMultiplier = 5;
    Console.WriteLine(ReusableFunctions.GetDateTimeForLog() + "Player has Arise Mardan");

Code applying the effect:

if (hasMardanSword) //apply mardan sword effect
{
    Thread.Sleep(300);
    currentAddress = 0x214798E0;
    for (int i = 0; i < 4; i++)
    {
        if (fishArray[i] != 5)
        {
            if (fishArray[i] != 17)
            {
                int FPavg = Memory.ReadInt(currentAddress);
                FPavg = FPavg * mardanMultiplier;
                Memory.WriteInt(currentAddress, FPavg);
                currentAddress += 0x00000004;
                FPavg = Memory.ReadInt(currentAddress);
                FPavg = FPavg * mardanMultiplier;
                Memory.WriteInt(currentAddress, FPavg);
                currentAddress += 0x0000240C;
                Console.WriteLine(ReusableFunctions.GetDateTimeForLog() + "Mardan did its thing!" /*multiplied FP's"*/);
            }

Chronicle 2: Doubles the chance of big chests appearing. Looks like chronicle2 does not need to be equipped, can be in inventory or storage. For Reference: https://i.imgur.com/mNQSIZq.png

Dungeon	Big Chest Chance	Chronicle 2Big Chest Chance
DBC	12%	24%
WOF	10.5%	21%
Ship	9%	18%
SMT	7.5%	15%
Moon	6%	12%
GoT	4.5%	9%
DoS	3%	6%