There may be a reason he's doing it - what feed are they on?
How many quail in one cage? One male?
Is there hiding places/things to break line of sight?
Usually it's improper feed/overcrowding causing these problems - if it's not environmental and just mental, I would consider culling as you don't want to pass along those aggressive genes on, if that's what's going on.
You can also try partitioning the male (they are side by side and can see each other but not hurt each other) and allow the other birds to heal fully, perhaps by the time that's done when the partition is lifted he won't have "the bloodlust" any longer!
At the very least it seems you'll have to remove him until the other birds heal completely because pecking at wounds/feather pins is something that even a normal non aggressive quail is apt to do.
Good luck!!