Here's the translated material for King Hassan that my friend gave me. Sorry for the long post in advance
The first to take upon himself the title of "the Old Man of the Mountain" (Õ▒▒Òü«þ┐ü, Yama no Okina) and the name of Hassan-i-Sabbah. Even so, his actual identity was unknown even to the eighteen individuals who came to inherit his titles. Proof that he in fact existed is nowhere to be found -- except in the certainty that if ever he who takes the seat of Hassan-i-Sabbah strays from his path, there shall come an executioner to part him from his head.
There was within the sect of the Hashashin not a single witness who could attest to the existence of the original Hassan; all of those who encountered him met their end. He who forged the name of "the Old Man of the Mountain" elected to live as an observer who would enact judgment upon the rot and the deviations of the sect. Even were the sect to persist in righteous accordance to the doctrine of Allah, it was inevitable that those avowed carry it forth might sin -- but for the preservers the doctrine to lose themselves to the desires of man was to the Old Man of the Mountain the gravest of sins.
To him, the rot and the corruption of the sect were equivalent in meaning to the waning of its leader. Whether by the waning of spirit or the waning of skills, one upon the threshold of decline could no longer be seen as fit to hold the title of "the Old Man of the Mountain." The sin of degeneration could be answered only by beheading -- such that the hopes of the sect could be entrusted to a successor.
He who assassinates the assassin -- who enacts the carriage of justice against those would stray from the doctrine of the sect -- chooses not to employ an assassin's tools of trade; he approaches openly and without deceit, carrying only a broadsword. Should a man come to glimpse the skulled swordsman, his existence is as good as concluded.
Unto the end of the Hashashin, the skulled swordsman concealed himself within the shadow of the sect; persisting as the very Abyss (µÜùµ«║ÞÇàÒü«µÀ▒µÀÁ, Ansatsu-sha no Shinen, lit. 'the abyss of the assassins') -- a living legend in the absence of a single witness.
King Hassan holds the Rank C Anti-Unit Noble Phantasm The Angel That Announces Death / Azrael ( µ¡╗ÕæèÕñ®õ¢┐ / ÒéóÒé║Òâ®ÒéñÒâ╝Òâ½ , Shi Koku Tenshi / Azura─½-ru). Though the broadsword that he bears is perfectly commonplace, it has across the lifespan of its wielder been stained in the colors of his faith. As a sword borne by a man who walks unto the boundaries of the Valley of the Shadows of Death (Õ╣¢Þ░À, Youkoku), its edge can potentially impose the termination of life with the slightest cut. Though the occurrence of this imposition is uncertain and low in probability, so long as it comes into effect, any opponent can be instantaneously felled.
Those that walk within the Valley are as one with Death, and are as such resistant to its instantaneous imposition, as well as the effects of mental interference.
Presence Concealment (µ░ùÚàìÚü«µû¡), Rank A -- the capacity to eliminate one's presence. Effectively, the remains of a skill acquired long ago. Being that the skillholder in question is a swordsman who bears upon his person a curse of immense strength, even if an attempt at the concealment of presence is essentially flawless, any target to which the skillholder intends mortal harm would be capable of discerning the existence of a threat.
The Evening Bell (µÖ®ÚÉÿ, Banshou) signals the announcement of funereal proceedings; the visitation of Death. This unique skill manifests in consequence of coming to be one in existence and being to the rites of passing. The swordsman of the Evening Bell is without agency in his choice of opponents; he is the manifestation of momento mori -- the divine salvation that befalls all of those who have lost sight of their mortality (µ¡╗Òü¼Òü╣ÒüìµÖéÒéÆÞªïÕñ▒ÒüúÒüƒ). A termination is brought upon the fates of those who would oppose the heavens; a final opportunity is granted unto those who stray, that they might come to rest while they remain as men.
I bolded some part that i found to be important. The valley thingy has "Boundary" in it and what it does is the same as what we have currently for King Hassan's At the Boundary description. Personally found it legitimate