Crimson Stone is one of the two greatest treasures of the vampires. The Crimson Stone allows its owner to use the soul of a vampire as a power source. Unfortunately it bears the curse of the vampire so a human using it would also become a vampire. It was believed to be lost along with the Ebony Stone.
As it turned out, Mathias was in the midst of creating it. He then had Death absorb Walter's soul (after Leon had defeated him) into the stone, thereby completing it. In doing so he achieved his ultimate goal - eternal life.
One additional benefit of the stone is that Death offers his allegiance to whoever possesses the Crimson Stone.
The Crimson Stone is a reference to the final stage of the Alchemical work, the rubedo/reddening. It represents transcendence, perfection, immortality, and incorruptibility. All these associations take on a very sinister double meaning with regard to what the Crimson Stone truly does in Lament of Innocence.
Crimson Stone
The Crimson Stone is one of two of the greatest treasures to the vampires, the other being the Ebony Stone. Both were believed to have been lost. The Crimson Stone uses the soul of a vampire to give its user power; however, at the same time, it also bears the vampire's curse, meaning that whomever uses the Crimson Stone will turn into a vampire. This was the case for Mathias, as he was in the midst of the creation of the Crimson Stone.
History
The Crimson Stone was obtained by Mathias Cronqvist. His scheme was to use the Crimson Stone to obtain eternal life and defy God for the death of Elisabetha. When Leon defeated Walter, Death immediately took Walter's soul to use for the Crimson Stone. The Crimson Stone became complete, granting Mathias eternal life and the curse of the vampire. He became the Lord of Darkness and the Crimson Stone has remained in his control ever since.
Trivia
- The only known vampire's soul contained within the Crimson Stone is that of Walter Bernhard, though it is assumed more have been collected in the ensuing centuries.
- It has not been in the posession of any other vampire other than Dracula.
- Dracula has command over Death due to his posession of the Crimson Stone. Death offered his allegiance to the one that holds it.
- The Crimson Stone is unique in the fact that it is the only other known way to become a vampire other than the traditional "blood gift."
Fans Speculation
The Crimson Stone holds the soul of the powerful vampire, Walter Bernhard. With the soul of a powerful vampire, Dracula was granted his incredible powers. The Crimson Stone feeds Dracula power by way of a three-step process. The stone absorbs chaos energy, it uses this energy to build a physical manifestation of chaos (Dracula's castle), and this physical manifestation focuses power to a singular point like a magnifying glass, thus resurrecting Dracula. Whenever Dracula dies, his soul is pulled back though his castle and filters back to the Crimson Stone, hence the destruction of the castle whenever he is defeated. This endless loop is one of the reasons Dracula constantly revives and how dark priests can speed up the process by offering extra power.
In a lot of the Castlevania games, the player is required to hit the pendant around the Count's neck or his head. Probably not the Crimson Stone itself (as he has been defeated with it on), it might be a focus for the castle's power. Dracula has transformed into a monstrous form after his initial phase in almost every game, perhaps signifying that the stone he wears becomes unstable when attacked.
In 1999, Julius Belmont sealed Dracula's castle, and the source of his power and means of resurrection, away into a solar eclipse with the help of Japanese priests. His pendant cut off from his source of power and his soul unable to return to the castle on his death, Dracula was slain once and for all. His soul shattered into fragments of his former power and attached themselves to children born at that exact moment. However, the stone itself, which Dracula sealed within the chaotic realm on the other "side" of his castle, was still intact.
When Soma Cruz entered the castle in 2035, he started absorbing the chaos energy that the castle was putting out. His power of Dominance awakened and he started absorbing the souls of the monsters in the castle. Upon defeating Graham, he absorbed the last of the power that Graham had been collecting and reestablished the connection with the Crimson Stone.
Unwilling to become the next Dracula, he managed to find the entrance to the realm of chaos with the help of Genya Arikado (Alucard), Julius Belmont, and Yoko Belnades. The final boss of this optional ending is a giant red stone (the Crimson Stone, though not explicitly stated) which focuses power to Dracula though his castle. With Dracula slain, the castle sealed, and the Crimson Stone destroyed, the cycle finally ended.
Spoilers end here.