Cielonos/Assets/Scripts/MainGame/Items/PassiveEquipments/VipersFang.cs

using System;
using Cielonos.MainGame.Characters;
using SLSUtilities.General;
using UnityEngine;

namespace Cielonos.MainGame.Characters.Inventory.Collections
{
    public partial class VipersFang : PassiveEquipmentBase
    {
        public override void OnObtained()
        {
            base.OnObtained();
            Action<AttackAreaBase, CharacterBase, AttackResult> onStartAttack = OnStartAttack;
            player.eventSm.onStartAttack.Add("VipersFang", onStartAttack.ToPrioritized());
        }
    }

    public partial class VipersFang
    {
        private void OnStartAttack(AttackAreaBase attackArea, CharacterBase target, AttackResult attackResult)
        {
            float targetHealthPercentage = target.attributeSm["Health"] / target.attributeSm["MaximumHealth"];
            float extraDamage = passiveAttributeData.itemAttributes["ExtraDamage"] * (1 - targetHealthPercentage);
            attackResult.attackValue.additionalFlatDamage += extraDamage;
        }
    }
}