Otherwise known as He Whose Name Cannot Be Spoken.
This apparently is an ancient Malkavian, sire to Marcellus and Strauss who was put in a dimensional prison and now has escaped, thanks to the efforts of the characters' coterie.
The tapestry, The Book, and the chessboard were all thought to be doors to his prison and we have watched, seemingly helplessly, over the years as they've weakened. Furthermore, it is rumoured that speaking his name causes bad things to happen. Strauss fears Achadremenos wildly but is compelled to help him anyway.
Many have had allegiance to him and it is feared what will happen now that he is walking among us once more.
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