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. 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.

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.

I will change Bloodcasting, I was unclear on that aspect of the system.