I have a Chaos Sorcerer with Warptime that I attach to a squad of marines. In the CSM Codex it reads-
Warptime
This power is used at the start of any player's turn. If successful, the psyker may re-roll all rolls to hit and rolls to wound for the entirety of that player's turn.
I thought this meant that just the sorcerer could re-roll, but one of my friends is convinced that it allows the entire squad to re-roll. Any thoughts/help would be very much appreciated!