Added Effect based on HP

Added Effect based on HP is a passive effect that adds an effect when the unit's HP reaches a specified amount of HP left. This effect cannot be stacked with itself if both buffs provided are the same

Examples of stacking

 * A unit with less than 50% HP under Lofia (Omni) and Hellborne Honeypot Luina's Leader Skill would have 20% damage reduction and 3000~3500 gradual HP regen.
 * A unit with less than 50% HP under Lofia (Omni) and Weald Guardian Nagid's Leader Skill would have 3000~3500 gradual HP regen, with Nagid's 2000~3000 HP regen effect on his Leader Skill to be ignored.