Caster
"Do you think demons exist kiddo?" Uryuu Ryuunosuke began, already liking the kid's expression. "The news keeps calling me a demon, but I think that's a little rude if demons actually do exist, don't you think so?" Uryuu waved his ancestors' notes at the kid. "You know, I found this old book while digging around my storehouse! It looks like my ancestors were trying to summon demons. So like, I gotta see if demons actually do exist! But if one actually does pop out, I'd have to be pretty dumb to not offer it something. So kid…" He then patted the boy's shivering head and asked, "If a demon actually comes, do you mind if we let it kill you?"
"MHHH!" The boy cried into his gags and began thrashing around in a desperate attempt to get free.
"Ahahahaha!" Uryuu laughed while jumping up and down. "I wonder what it's like being killed by a demon! I bet it would be pretty coo-ow!" Uryuu then grimaced as his right hand felt like it was on fire, and looked down to see three scythe-like red crimson markings appear on it. The circle then began to glow before billowing out smoke.
When the smoke finally cleared, the mad mass-murdering young man could see that he had summoned something. Someone actually – a tall man in his late forties. He had light-brown hair, most of which was short and spiky, save for three thin braid on the back of his head. His eyes were hidden behind round black glasses, but a tattoo that looked like a barbed wire drawn across his face at the eye level could still be seen. The ...demon was wearing long light-gray overcoat with a high collar and ridiculously long sleeves; it also had a strange symbol in blood-red on its back and two pairs of... some sort of protrusions on the shoulders. The rest of the summoned man's garb consisted of dark-gray pants and black combat boots.
"Cool!" Ryuunosuke exclaimed as he observed the Servant he had just summoned – not that he knew about that. "See, boy, I've summoned a demon and now you will become his dinner! Isn't it cool!" The boy in question once again tried to free himself, but he had once again failed – Uryuu had tied him pretty well.
"I'm afraid, I'm not a demon." The summoned man stated. "Nor I will eat this little yellow heretic." Ryuunosuke artistic mood seemed to evaporate instantly. "But I will be more than happy to purge this thing from the face of the Earth. Want me to do this in a... creative way?" Now, Uryuu was grinning madly again.
"Ma-a-an! You're so cool!" The mad mass-murdered exclaimed. "What, what do I have to do? Tell me!" The still-unnamed man thought about it for a moment, before replying:
"Bring me some water." Ryuunosuke, who definitely wasn't expecting something like this, but still hurried to get his fellow 'artist' what he had asked. Meanwhile, the Caster of the Fourth Holy Grail War approached his soon-to-be first purge target within this world. "Listen here, filth, I will kill you now: yellow heretics like you don't deserve to live. Your death will be long and painful, and I want to hear every second of it, got it?" Then he turned to his summoner, who was carrying him a bucket full of clean water.
"Here you go." Uryuu said as placed the bucket next to cloaked man. "Now show me how you kill this kid!" The summoned man let a cruel smirk make its way onto his face, before he bent backwards and placed his apparently-gloved hand into the water. Then, much to Ryuunosuke's shock the bucket itself melted, while some clear but highly-acidic liquid was hanging in the air around the not-demon's hand.
"Time for a purge, kid." The cloaked man said, before ...well, throwing the liquid at the kid. Within seconds the clothes on him began melting, followed by the body flesh. And since the little boy was no longer gagged, he was screaming his throat raw as the deadly acid dissolved him.
"That was so-o-o-o co-o-o-ol, man!" Ryuunosuke exclaimed, as he processed the way his new 'partner' had killed the kid. The not-demon allowed another smirk creep onto his face.
"Good, I'm glad you've enjoyed the show!" Then his smirk turned even more malicious than the one he wore when dealing with the kid. "Because you're a yellow heretic too, I have to purge you!" The underground chamber then started filling with light yellow-green gas that was pure chlorine. Needless to say, Ryuunosuke didn't last long, but at least he got to enjoy his own torturous death...
~/ *** \~
Before the night was over, all remaining six masters had received a missive, where Risei Kotomine was telling that Caster had went berserk and, after killing his own master, started eliminating the local population by gassing them Chlorine. Since it appeared that Caster had no intentions but to kill anyone he laid his eyes on, Risei felt that giving the remaining masters some information about this abominable Servant was not a bad thing to do.
And to further motivate the masters to kill Caster, Risei also promised the three command seals (taken from the Uryuu Ryuunosuke's body) to the one who managed to rid the world of the walking gas chamber that this Caster character apparently was.
By pure coincidence, Waver and Rider were the first ones to find Caster. The two of them were simply returning from the local mall with some groceries when they caught a glimpse of the rogue Servant disappearing into a side alley. Already knowing when that not-Heroic spirit had done, the two of them immediately followed him, ready to end his existence.
~/ *** \~
Caster was observing some local school from a distance. While he didn't really care whether some yellow saw him at work – he will kill them all anyway – he wanted to be the most effective with his kills, and so he waited for when there will be the greatest concentration of the yellow heretics at this location... His thoughts, however, were interrupted when far from subtle, lightning-spewing bull-driven chariot entered the street where he currently was. Since that could only be some other Servant's noble phantasm, Caster knew that this time he had to be really serious. Even if his opponent wasn't Rider, being run over by a massive chariot didn't sound like a fun way to start a day to him...
Caster managed to dodge the chariot's charge, though not completely as he was both thrown aside by something attached to its massive wheels and electrocuted by the lightnings. And while that had hurt, a lot actually, it placed his quite close to a puddle that was there on the asphalt after the rain that had happened this last night. And having some water to use...
Iskandar was shocked when Caster managed to wound his divine bulls and destroy the reins (along with half the front of the chariot) by throwing some clear liquid at it. And now that he and his masted had dismounted, the abomination of a Servant was preparing another acidic attack in hope of killing them both... No, that wouldn't do.
Rider charged at the other Servant, ready to behead him with his short sword, but much to his surprise, Caster managed to dodge quite easily and haven't even lost his control over that acid, which he immediately threw at Waver in a form of a homing stream. Needing to protect his master, Alexander had to stop trying to chop Caster into pieces; quickly taking of his red cloak, he threw it over Waver, thus protecting him from the deadly liquid... Damn, he liked his cloak so much...
"This madness shall stop now." Iskandar exclaimed and a moment later a ring of ghostly fire burst from his body. Then both Rider and Caster disappeared, leaving a shocked Waver alone in the back alley.
Rider and Caster found themselves in the center of the endless desert. Sure, Alexander thought, maybe using his reality marble against such an opponent was a bit of an overkill, but he simply couldn't allow this bastard to harm his master. And with how Caster was throwing those blobs of acid around, it would have been an almost impossible task had they remained in the proper reality.
"So... You took water away from me. Clever." The mad acid-using genocidal Servant stated. "And this place is so-o huge. It'll not be an easy task, but I still can turn into into my gas chamber! You shan't stop me, Rider, as I have to rid this new world from heretics and..." Caster was forced to shut up and dodge as Iskandar charged at him again. "I see... Interrupting a man when he is speaking... how improper." And with those words he started releasing deadly gas from the sleeves of his coat. The rapidly-growing cloud forcing Rider to step back, lest he keeled over. "So... What are you going to do now?" Iskandar didn't need to answer as this very moment the vast army he had commanded during his life arrived: thousands of warriors appeared from behind the dunes like a living sea.
"Spearmen!" Alexander the Great commanded in a loud voice that could be heard for miles. "Kill this man!" And with a thunderous shout of agreement, at least two thousands of spearmen started throwing their weapons at Caster. And no matter how fast and agile the bastard was, dodging that many spears was beyond even him... Within just a couple of seconds he was screwed by a great number of spears in such a way that no normal human had even a faintest chance to survive. Yet, Rider didn't order his men to stop until Caster had disappeared in an explosion of sickly-green sparkles...
Caster
True identity: Croa 'the Purger'; also known as 'Gas Chamber' for the way he likes to kill his victims.
Series: "Seikon no Quaser"
Age: unknown, ~40
Sex: Male
Alignment: Chaotic Evil
Strength: C
Endurance: C
Agility: B+
Mana: C+
Luck: E
Independent action: C+ - however he can gather prana needed to keep himself in this world from alternative sources.
Magic resistance: D
Battle Continuation: C
Territory creation: E-
Eye of the Mind (false): C
Noble Phantasms:
Quaser of Chlorine: B++, support, anti-unit, anti-army, permanently active. Croa as a Quaser has control over the element of Chlorine. He can use this ability to create various gas attacks or, combining chlorine with water, he can create deadly acid, which he can control freely. This ability, though, has his relying on mystical energy he gets from maidens that experience strong emotions (he usually does the 'feeding' through rape).