Quote Originally Posted by Sylve View Post
-Blood Weapon is mutually exclusive to Blood Price.
Well, it's a little more complicated. Sure you can't use them at the same time, but you still technically use one when the other is on CD, so "fusing" them on a single slot can be tricky.
You don't have this issue with FireIV/BlizzIV or LeyLines/Between the Lines, since one pair is on GCD and for the other pair, one skill is a direct condition for the other.