The rules for casting a blessing and maledictions are as follows.
Blessings are manifested at the start of the Psyker's Movement phase
Maledictions are manifested at the start of the Psyker's Movement phase
Now does that rule mean it is cast at the beginning of the movement phase or before you move the psyker?
My belief is that it is cast at the beginning of the movement phase. An example that i know well about is the eldar farseer powers. If you'd hypothetically group fortune and guide into one of the types of spells, they'd probably fall into the blessings category as there are already spells strikingly similar there. Also doom would probably fall under a malediction spell, and in the eldar codex they specifically state that those spells are cast at the beginning of the turn which leads me think that that might be the case for all types of blessings/maledictions.
The only threads i can find about this are these:
If you can find anymore, or any that says the otherwise, please post it here.
Let me know what you guys think on the matter?