well, no one's forcing you.
duly noted
(and with that, she ends the conversation, there doesn't seem to be any reason to keep it going.)
Other options:
no subject
Don't know what I could do. Magic's not my area.
no subject
well, no one's forcing you.
no subject
If something needs killing I might think about it.
no subject
duly noted
(and with that, she ends the conversation, there doesn't seem to be any reason to keep it going.)