What is true Magicae Impentum :0 what does it do what does it mean how does it affect those who has it I assume it has something to do with magic use or flow within those afflicted (especially with half the cases so far dying young)
Is it only present in skeletal monsters? Or all monsters?
Oh boy I am so glad you asked!! This will be a lot so please do ask if you need anything clarified!
Magicae Impentum has 2 different types, one being fairly common and possible in any monster, the other being extremely rare and only possible in certain types of monsters.
The first type is minor or false Magicae Impentum. This can occur in any monster and really just means the monster was born with more magic than usual. There are varying levels of severity but it's generally not fatal and fades before the child turns 5. Only extreme cases (which are rare) and unmonitored cases really result in death. It honestly more dangerous for the parent than the child in most cases.
The second type is major or true Magicae Impentum. This type, as you know is much rarer. It's also only possible in monster species that naturally have high magic content. For example, elemental monsters (made of pure magic), skeletons (made almost entirely of magic), and elemental hybrids are the most likely to suffer from this condition. True Magicae Impentum is when the sufferers soul produces more magic than the body can handle. The soul is constantly in a state that would be considered a massive overdrive for other monsters. This causes the soul to work itself to death or the excess magic to slowly eat away at the soul.
The excess magic has a wide variety of symptoms that vary depending on how bad the magic buildup is on a particular day. Sufferers often deal with fatigue, chest pains, inability to sit still, severe anxiety, etc. Some sufferers will also experience random but severe bruising.
The biggest problem this causes though is that sufferers absolutely cannot intake any extra magic that isn't immediately converted into energy. This is a problem because monsters with that much magic require food high in magic to properly digest it. Most deaths to this condition are actually caused by starvation because they couldn't process food before their body goes into defense mode. The body will react violently to outside magic that takes too long to be converted to energy. This includes healing magic. This also means that they are more sensitive to magic attacks. Though it does also mean monsters with this condition have much stronger magic.
The most dangerous aspect of this condition for those who survive is outbursts. Outbursts occur when too much magic builds up and forces its way out of the body. This is extremely painful and causes severe damage to the soul. Magic explodes out of the body with no control which can cause damage both to the sufferer and anyone nearby. It also often causes the sufferer to go into comas.