Hey, you think after you guys accepted a job that this plane's going to just let you go without it getting finished? Ha!
Mixster, still need to know what spell or item and the source it's from, that you used to stop the breath weapon and Blasphemy. I can't draw it up if I don't know the details.
And if it's an immediate effect that can be heard, then the bar-lgura will likely not have moved from where he was.
It's complete Arcane, Iot7v. He places a warding between Melkior and the origin of the effect, saving those that are behind it. (If you draw a line directly from the point of effect to Melkior, Alkazar will place his warding in the middle between them and perpendicular to the line). The wall is 70ft long, and 35ft high plenty of length to block the blasphemy entirely.
I don't think it can be heard, but I'm uncertain, it doesn't say it has an audible component, yet neither does it say it has. If anything moves through it from the direction Melkior is not in, they will have to pass two will saves, the first to avoid being confused as the insanity spell, and the second to avoid being planeshifted to a random place on a random plane.
Melkior does have some revenance/revivify combos ready, so no need to re-roll just now
EDIT: Initiate of the sevenfold veil can be found in complete arcane Page 45. Page 46 describes the "wall" warding, and also has the Indigo and Violet warding that stops all effects.