Malakath creates the concept of 'Oversoul'.
Oversoul:
When a sapient being completely masters all primary forms of power available to it (physical, chi, and (if they're magic-capable) magic), they have a chance of going Oversoul: getting a x10 multiplier on all forms of power and going through a noticeable change of appearance for a limited amount of time.
All mortals are theoretically capable of oversouling. It's actually easier for a non-magical being to gain access to Oversoul but magical beings who access Oversoul are quite a bit more powerful than their non-magical brethren, simply because they would be just as powerful in the physical and chi departments but they would also have access to magic.
Appearance changes tend to vary from race to race and even person to person. Some gain a standard aura, some a wavy one, some get some colour changes, for some it makes their hair grow....some can even get new body parts! The appearance of the a being's Oversoul state can also change as it its soul changes in personality or emotional charge.
Once a being reaches the apex of its own power, it is capable of going Oversoul once a particular emotional trigger is hit. It could be rage, despair/grief, determination/willpower, or transcendence/focus. A combination of emotions also work. Watching your family get killed would be both incredibly sad and incredibly rage-inducing, thus providing a stronger catalyst for getting to Oversoul.
Oversoul plays off of the metaphysical aspects of the soul, rather than its physical or tangible aspects that are usually focused on. It's all about that particular being's ability to be the best it can be relative to its difficulty in attaining the mode. Thus, it is just as difficult for a Human to reach Oversoul as an Ikaku or a Golem.
Artificial drive to attain Oversoul or simply become more powerful is considered to make it easier and it would be proportionally and inherently harder for it to attain its goal, more or less as difficult as someone without the artificial drive simply because their soul will need have even stronger emotional charge. Thus, if a god (ANY god - including gods of Souls or Emotions) simply gave a being more willpower, stronger sensitivity to emotions, giving it immortality, or something else so it can get to Oversoul faster, it simply won't work. Trying to find ways to go around this rule like putting the being in a dimension where time moves faster (thus decreasing the "real time" it would take to meet the physical requirements) will only lead to disappointment.
This rule doesn't just apply to gods, though. Mortals attempting to make it easier using Psymental or Soul magic will have equal amounts of success.
The whole rule only applies to attempts to artificially alter the being itself to make Oversoul an easier goal for it to achieve. Doing things like making the being watch all its friends and family being killed right in front of it as it's forced to watch impotently would get the being to reach Oversoul faster.
It's more difficult and thus takes a lot longer for an immortal being such as a High Elf to attain the form because the odds that it will eventually meet Oversoul requirements are relatively high, simply because they have so much time to complete the requirements. It's still possible for an immortal being to get to Oversoul, though, but it's definitely not possible for them to reach Oversoul level 2 (*see Oversoul 2 below). They have the option, however, to sacrifice their immortality to a relevant god to reach those levels. It is also the only way to make getting to Oversoul easier, but only because they now have a limited time to attain it before they die.
The possibility for an angel being able to Oversoul is so small it's actually rather laughable. Even worse is that it could theoretically be impossible. Oversoul relies on a being having a strong soul and becoming as physically powerful as it could possibly be. The problem here is that if angels don't have these power limits, they would never be able to get to Oversoul because reaching and surpassing limits is the whole point of Oversoul.
Gods straight-up can't get Oversoul ever because their capacity for emotions and/or power is (perhaps literally) infinite.
There's a general path a being follows as it attains oversoul. As it gets closer and closer to meeting the requirements to attain Oversoul, the being will occasionally get Oversoul "surges".
Surges tend to occur either when emotions flare up or during a particularly strenuous burst of physical activity.
Oversoul surges are basically demos; they multiply power the being's power and change its appearance, but not as radically as true Oversoul would. The effects of the surges are relative to how close the being is to Oversoul - the closer they are the greater the multiplication of power and the more radical the appearance change. The multiplication in power tends to be from barely anything higher than a x1.1 multiplication up to a x3 multiplication.
These surges are only active for a very short amount of time - a split-second to about a second and a half. As such, the being can usually tell that they've experienced a surge only after it's passed. Of course, the amount of time a surge is active is greater the closer the being is to attaining Oversoul.
As the being gets closer to Oversoul, it will begin getting more and more surges closer together. Once the requirements are passed, the body starts getting surges regardless of if there are any physical or emotional triggers. The space in time between surges begin with minutes in between each. The time shortens on its own after each surge until it's practically consecutive. At that point, a surge will be constantly maintained for a few seconds before they get a truly massive surge in power and their appearance changes drastically.
The being has attained Oversoul.
This initial true Oversoul lasts for about ten to twenty seconds and the being will feel rather exhausted immediately after.
After the being attains Oversoul (and has a good night's rest, most likely), the being will from then on be able to access Oversoul whenever it wants and can never lose the ability.
The time the being will be able to use Oversoul is initially rather small - only about five seconds - and will always feel very tired afterwards (though not to the same degree as the first time) and will have to rest a bit before it can oversoul again. Simply using Oversoul increases the time that can be spent in the mode the next time it's used, especially if the being actually uses Oversoul's power while they're in it. Going a long time without oversouling will eventually decrease the time it can be used each time in the same way that muscles atrophy when not in use.
Getting less powerful (in terms of base power) does not decrease the time that the being can use Oversoul in any way so long as they continue to use the state. Similarly, there is no penalty if the being regains its base power after losing it.
If the being is physically altered to be less powerful (such as if a god gives them the combat-diminished trait), Oversoul will simply compensate by increasing the multiplier until it's just as powerful as it would normally be while in that state. The inverse will happen if the being was getting physically altered to be more powerful.
Once a being masters Oversoul to the point where it could live its entire lifespan in Oversoul plus a few more years, the being will automatically go into Oversoul 2. Oversoul 2 alters the being's appearance even more radically and multiplies its power by x10, effectively multiplying its base power by x100.
The time that a being can remain in Oversoul 2 will be equivalent to the amount of time it could spend in Oversoul 1 when it first used it on purpose and the being will similarly revert to base form in a tired state. Training is a lot more difficult, though. Instead of using its power in Oversoul simply speeding up the process, it's actually mandatory to increase the time limit on Oversoul 2. Moreover, the being would have to train as hard as possible during the entire time and even then it would still take longer to increase the time limit that it would for Oversoul 1. Finally, there's a hard time limit of half an hour that simply cannot be surpassed regardless of how much training is done. It would, however, increase the time before the time limit starts atrophying after disuse of the state.
The reason why an immortal being cannot under any circumstance access Oversoul level 2 is because it is necessary for a being to be able to hypothetically live out their whole life in Oversoul level 1 in order to achieve Oversoul 2. If the being's lifespan is infinite then it logically cannot ever meet this requirement. Thus, it is necessary to permanently give up its immortality to a relevant god. It can give it to a mortality god, a soul god, a racial god (if the sphere and race align), a time god, a sacrifice god, or any other god that is definitely relevant to the sacrifice of immortality. The being will choose how long its new lifespan will be at the time of sacrifice.
Once a being manages to train Oversoul 2 all the way to its maximum time limit, it can use Oversoul 3 - also known as Maximum Oversoul - whenever it wants. It changes the being's appearance even more radically and multiplies its power by a massive x15, effectively increasing its base power by x1500. The state lasts for a flat thirty seconds. This amount of time cannot be increased or decreased. The being will NOT automatically go into Oversoul 3 as soon as the requirements are met.
The being needs to make a very purposeful decision to go into Oversoul 3. Any physical alterations to the being that would make it more or less likely to access it will also increase or decrease the purposefulness necessary for the being to go into Oversoul 3 accordingly. Ditto for the time limit.
The reason why Oversoul 3 is known as Maximum Oversoul is because there is no higher level of Oversoul. Oversoul 3 is as high as one can go. The reason why it's so important that the being chooses to use Oversoul 3 is because after the thirty seconds are up, the being's soul will be entirely destroyed. The being will intrinsically know the effects of activating Maximum Oversoul.
For a being to attain Oversoul, it must be sapient and it must have a soul.
Void worshippers cannot attain Oversoul because they by doing so they corrupt their own souls. Souls = the things that are absolutely critical to achieving Oversoul. So yeah, no Void stuff.
The being must truly align itself with a god relevant to the aspects of Oversoul. It can be a a soul god, a racial god (if the sphere and race align), an energy god, a magic god, a body god, or any other definitely relevant god. By 'truly align', it's meant that it cannot simply feign devotion to the god or alter itself to be devoted up until it reaches Oversoul or something. Continued devotion must be kept with a relevant god for Oversoul to be possible.
Simply achieving Oversoul would be incredibly rare to the point that only a handful of people (~3-8) on a planet would be able to reach it every generation. Oversoul 2 is rarer at only a few of those who've accessed Oversoul 1 (~1-3) can access it and it's entirely possible that there aren't any on the planet who can. The idea of someone being able to attain the messianic power of Oversoul 3 would be so rare as to be considered a subject of prophesy.
The idea of Oversoul is that it is pure. It cannot be meddled or altered or gamed. It's so potentially powerful that it's necessary for it to remain pure. It is a gift that cannot be abused and cannot be allowed to be abused.
Lord Malakath informs the mortals about what oversouling is and tells them to find a Soul temple for more info on how to gain it.
Lord Malakath's new symbol is that of a white circle with a tinge of blue mixed in. It has a small red aura around it and a drop of blood is dripping from it.