[quote]Words of power will literally kill him if he tries to pull off anything large or extremely complicated. I can change how the ability works, I suppose. The way I think of it is like a summoning circle, but instead of, I dunno, summoning something as powerful as a magic servant from the depths of history he can use it to create simple objects by describing them. The paper is consumed in the construction and it will take matter from the area around it, I'll add that too. [/quote]

That's closer to Alchemy than anything else, but it's not just alchemy because you need Structural Analysis and not just a word in order to create what you want. Also you need more than writing down a word; you'll need an aria, you'll need a magic circle, etc. 

[quote]Rune magic exists in the Fate world, and this is honestly just rune magic that uses English (or whatever language our characters are ostensibly speaking) instead of ancient symbols in the case of the fireball spell. Easier, yes, maybe. Limited to paper instead of being able to just draw the symbol from a distance? Yes.[/quote]

Oh. Yeah, that doesn't really work. Runes generate mystery because of their origin; in Nasuland, the giants of Scandinavia and whatnot invented the runes, they're originally a Phantasm Race demi-human deal. Modern day runes have inherited some of that mystery, such that passing prana through the symbols accesses that Magical Foundation. It's all about the Magical Foundation. Modern pleb English doesn't have a Magical Foundation, so that won't work.

That said, you can totally have runes. Rune that shoots a fireball and stuff. That's fine. For your swords, there are other ways you can get a sword, like hiding it inside pages or something a la Ciel; that fits your guy's theme pretty well anyway.

[quote]As for the name thing, he cannot just write a name like "Saber" down and get anything off of it. He has to write the full real name of the person in question, and he can't magically tell what it is–it has to be told to him. The information will appear on the sheet of paper where the name is written. His incantations are in the form of writing, which allows him to focus his efforts without quite as long a process as a long spell. It's a shortcut, but it also makes him dependent on the time and materials to write whatever it is he's trying to do down.[/quote]

No, see, you're not getting it. You literally cannot do that. Doing that is like accessing the Akashic Record or something. You're reaching into the data of reality via the "name" as a means of access to view certain bits of information. That's beyond modern magecraft. Hell, it's beyond AoG magecraft. It's just not a thing, and even if it was, having him would mean he'd be way too busy getting chased by Alaya-tan or something to bother with a Grail War. Heck, he wouldn't even need the Grail to begin with, he has his own route to [ ] already.

There is no spell that can do what you're talking about. Want to read someone's mind? Sure, you can do that to get info on them. Suggestion to make them tell you stuff? Feel free. What you're doing though, as it is now, is tantamount to accessing the Akashic Record.