L’ruk appears however he wishes to appear. To give him a single appearance is to downgrade the sheer power originally granted him. However, his original appearance, and still his most common one, is that of a winged warrior, clad in a shining breastplate, purest white robes, and sandals of unearthly quality.
As with all sin, the first sin was the Sin of Pride. The most beautiful, most powerful of all creations, L’ruhk, became prideful. His pride quickly grew into a self-obsession, and he quickly fooled himself into forgetting that the sole Being above him in power was the One that had created him. He desired to become the Master of All, and for his arrogance was cast into the Nothing Outside of Creation, banished from Creation and all its glories.
Were this the end of our story, Tyren would be a much better place, but alas, such is the err of pride that defeats are quickly overlooked once they’re past. L’ruk, now fallen from grace, turned his mind towards a forceful uprising against Trigu, and from the Nothingness Beyond forged demons, terrible servants that were imbued with a fragment of the Dark Prince’s essence. In addition, he also constructed a black spear known as Coivn for his personal weapon.
With this army of darkness he returned to Creation, determined to overthrow Heaven and Trigu Himself. The resulting pair of wars were eventually named the Demon Wars, and after much destruction and scarring of the face of Tyren, L’ruk was defeated.
For this second offense against his Creator, L’ruk was unmade, the fragments of his essence cast into the nothing from whence he had returned. However, when his spear was cast into the Great Sea (where the Maelstrom now spins), it became the new focus for L’ruk’s existence, for that was all that was left of him.
Thus remember, he is still powerful, and continues to manipulate events even to this day, trying to regain his lost power and overthrow Trigu.
This is the Great Evil in Tyren. There are no roleplaying notes, because if the players ever DO end up facing him, they will quickly become disabused of any notion of defeating this most powerful of all creations. This guy is so beyond the level of stats that he’s lost sight of the concept. So, he is background fluff.