Sorry had a major revision in mind but lost the file so I'm reposting the original with some changes
November first 1997
Xander walked into the library. Last night had interesting to say the least. He had went as Blade last night and had been wearing an outfit that had all of Blades' various weaponry and his many tattoos. Now he possessed all of Blade's considerable weaponry and martial arts skills, along with his knowledge of demonic languages and types of demons and their strengths and weaknesses. Xander had Blade's strength and speed. Thanks to what he had said before the spell he figured that was why he did not have the thirst. Although getting used to the enhanced senses was going to be a fucking pain. Another annoying part was the fact that Blade swore like a sailor.
He saw Buffy talking with Giles. "Are you sure Buffy?" The watcher asked his Slayer.
"Yeah saw someone after the spell had ended blow up a pair of vampires with vials of something. It was really gross seeing them expand and bloated before they died." Buffy said disgusted.
"Indeed, any other things you want to mention?" Giles asked.
"Other then the fact I'm fluent in French nothing." Buffy said.
"Well your not the only one with after effects Buffy." Xander said.
"What are you talking about Xander."
"I'm now fluent in eight languages and passing in at least ten others." Xander said shrugging "not to mention mastery of many forms of armed and unarmed combat." Buffy looked at Xander taking stock of him.
"Really." Buffy said not convinced.
"Yeah really want to try me or are you a fucking chicken." Xander said getting into a battle stance. As Buffy attacked him in angry about what he had just called her, Xander blocked her punch with a quick wrist lock and then followed up with a judo flip that sent Buffy to the floor of the library.
"Okay, I'm convinced. What's with the speed thought that was near vampire levels. And why the language." Buffy said getting to her feet.
"The guy I went as on Halloween was a martial arts master. And he is loose in the sense of what he says." Xander said smirking at the look of shock on Buffy's face.
"What?" Buffy nearly shouted shocked at what Xander could now do.
"Relax, Buffy he trained hard to get to where he was when I possessed him nothing mystic about him." Xander said coolly, staring at the Slayer.
"Good lord. How much did you retain?" Giles asked rubbing his glasses.
"Just about all of it." Xander said shrugging, "but seeing as Buffy has only a few after effects I'm wondering what type of spell it was."
"Chaos magic not a transformation spell." Giles stated, "Why is the type important I must ask."
"Well since it was chaos magic and the fact that I broke a seemingly unbreakable prophecy I figured that I have a high level for creating chaos." Xander said.
"Really how is that?" Giles asked.
"Buffy died for a few minutes in the cave so I figure that the Slayer essence from what I've read briefly on the subject transfers at death was using that logic I probably twinned the Slayer line." Xander said in a matter of fact tone.
"Are you sure?" Giles asked looking at Buffy who had a look of shock on her face.
"Might be wrong, but then again no one has managed to revive a Slayer who died before." Xander said keeping his eye on Buffy which was a good idea for a half second later Xander used a side kick to knock her down and out as she tried to charge him with a stake in hand. He figured she thought he was lying which he was but not in a way they would find out about.
"And Giles try to keep Buffy from slaying me." He said leaving the library while Giles went over to Buffy trying to revive her.
During computer class later that day
Xander smirked Jenny was a Romanian judging on Blade's memories of other Romanians he had encountered. "Anything you need help with Xander?" Jenny asked.
Xander smirked dropping into Romanian on purpose "No I don't."
"What?" Jenny replied in Romanian confirming Xander's suspicions.
"Interesting member of the Gypsy clan on the Hellmouth." Xander said still in Romanian.
"How?" Jenny asked now in English.
"Guy I went as on Halloween was a vampire hunter so that is how I know, how to find out what people are trying in terms of ancestry." Xander said smirking still in Romanian.
"You wouldn't tell Giles will you." Jenny said mortified.
"Not for me to say and also knowing Gypsy magic the spell on Angelus has a release clause, if I could take a look at the original now that I can understand the language it should be easy to figure out what the release clause is on the curse on his soul." Xander said in a near emotionless voice. "Also if he loses his soul don't try to find the curse, because I'll deal with the motherfucker."