Magic

The birth of magic dates back to the Celestial War, back when [forgotten for a reason.] slaughtered the Ancient Gods. The death of a god, no matter how insignificant is not something to be taken lightly. The corpses of the fallen, brazenly tossed aside were still brimming with power, just waiting to be unleashed. Magic in Tylien is deeply tied to these planetary corpses of the Ancient Gods, and the Ancient Gods on the other side of the Swathe. The way you start casting magic is by connecting your mind to one of the corpses (or Ancient God) in order to cast that type of magic. For example, if you wanted to cast lightning spells, you would connect your mind to the corpse of the Ancient God of Lightning. Casting spells is a matter of drawing the right amount of energy from the corpse in a specific pattern.

Imagine you casting spells as a beam coming from the planetary corpse of the Ancient God coming through the cosmos straight to you. Casting spells requires you to shape the size and shape of the beam in a way so that the energy coalesces and doesn't explode. This is why casting spells of harder levels is so fatal. It requires you to make complicated patterns and to not draw too little or too much power, often in tense circumstances. Creating new spells are often fatal, because it's just a manner of throwing random configurations of power and patterns at the wall and seeing what sticks and what explodes in your face.

Magicians often can dabble into other types of magic than the first one they start with, and can create fusions of different types of spells. If you can cast two types of magic, you can combine two spells from each type of magic to create a fusion spell that can be cast by anyone that can cast at least one type of magic.

The corpses of the Ancient Gods, while brimming with power, are not invincible. Back during the Age of the Giants, there was a type of magic called telekinesis. You know what it does, and it was an extremely useful magic, practically everyone that was anyone and some people that were no one could cast this type of magic. All this magic came from an Ancient God of Transportation & Other Related Things. During a battle between the Starchildren and the Voidborn, The Starchildren were pushed back to the corpse of the Ancient God, and during the ensuing battle, the planetary corpse was destroyed. This triggered an event known simply as "Severance." Basically, anyone who knew how to cast telekinesis (which was 80% of the giant population) died. Just instantaneous drop dead death. If you casted a fusion spell regarding telekinesis or connected your mind to the corpse, you were dead.

To spell out how magic works, the corpses of all the slain Ancient Gods are strewn about the cosmos. You connect to a specific corpse to cast a specific magic using a specific configuration of pattern and power to cast a specific spell. If the corpse you are connected to gets destroyed, you die.