Is there any significance to Risei's line?

Question

In episode 16 of Fate/Zero, we see Kayneth go to the church in a wheelchair to plead for a command seal. Risei Kotomine relents, and when transferring one of the command seals onto Kayneth's hand, we see this line:

Take this cup and drink from it. This is my blood, given to you, for the salvation of all. The blood of a contract!

(Translation from Crunchyroll subtitles.) Barring the bit about the contract, this is suspiciously -- to me anyway -- reminescent of the Christian tradition of the Eucharist. However, unlike the real world ritual, there is no actual cup here: Risei says this line while his hand is on Kayneth's.

Is there any in-series meaning or significance to this? (Is it part of the ritual of transferring "blank" command seals unconnected to a specific servant? Notice that when Sola-Ui forcibly takes Kayneth's command marks, nothing similar seems to appear.) Or is this merely symbolism or a reference thrown in for the sake of atmosphere? (Here, perhaps to give a sense of mysticism and foreboding to the Grail, given that blood, on its own, could have negative connotations? Or perhaps simply some sort of "Easter egg"?)

The latter explanation seems more likely to me, given what I've heard about a lack of knowledge of Christianity in Japan, but it could be that I'm missing knowledge about the workings about the Fate series universe.

I have not seen Fate/Zero beyond this. I do have some vague idea of how the Grail works from skimming over various Wiki articles or posts on this site, and from what has so far been covered in the current UBW adaptation.

Answer 1

This is just some unimportant ritual Risei thought up, possibly because he cared for the symbolism (being a devout priest), or that it might accentuate and reinforce his role as overseer. You'll see implicit evidence of this in later episodes:

After Risei is killed, Kotomine takes the command seals. He has to recite a specific verse of scripture to do this, thus reinforcing how Risei likes to add his faith into the things he does. He later convinces Kariya to use two of his command seals to kidnap Irisviel, on the promise that Kotomine will give him another fight with Tokiomi, as well as the grail at the end of the war. He wonders if it was really worth two commands, and Kotomine assures him that there is nothing to worry about. He simply places his hand over Kariya's command seal marks, and they are restored in a (literal) flash, and nothing more.