Create a Shortcut with Bloodbringer as the weapon but leave the familiar shard blank. The rest of the set doesn't matter. Next unequip your weapon and set Bloodbringer as a familiar. Then switch to the Shortcut you made. (You can also then save a new Shortcut with both set to make this quicker in the future.) The reason this works is because the game won't change some of your currently equipped gear/shards if there's nothing to change to in that gear/shard slot.