Sisters Vis are a boss added in the expansion The Binding of Isaac: Afterbirth † that can appear in all environments of Chapters 3 and 4.

Behavior

Similar to The Cage, Sisters Vis curl up in a ball and roll towards Isaac, bouncing off the walls. One of them leaves a trail of Green Creep while the other leaves behind a trail of Brown Creep. One of them will stop rolling before the other and will either:
- Fire a wide Brimstone laser at the player's direction.
  - Alternatively, this Brimstone laser may rotate nearly 180 degrees.
- Fire two, three or four lines of blood shots in a V formation at the player's direction.

Any of these attacks will finish a few seconds before the other Sister Vis stops rolling.

Spawns either two Vis or two Begottens.
The Sisters Vis will leap into the air and land one on each side of Isaac. They will then open their belly and fire wide Brimstone lasers towards where Isaac was when they landed. The two beams will hit each other and block each other, so that the damage field of the Brimstone only appears between the two Sisters.

When one of the two is killed, the other will become enraged, and will attack much faster.

If the Sister Vis that leaves Green Creep dies first, the other will leave Green Creep instead of Brown Creep.

Gallery

Sisters Vis are a cameo from the 2004 PC game Gish, created by Edmund McMillen.
- In Gish, they are the bosses of the 3rd area: The 7 Planes of Hehenna.
- As Sisters Vis are originally from Gish, the designs of the Vis enemies and The Cage itself originated from them.
On the Sisters Vis' bodies there is a Y-shaped mark, commonly known as an autopsy stitch. The stitch is commonly made at the start of a surgery, to get access to the insides of the cadaver. When the autopsy is complete, it's stitched back together
- The same stitching is seen on The Duke of Flies, The Cage and Conquest.
Sisters Vis were previously a cut-content boss that was planned on being added in Afterbirth.
Sisters Vis are the only normal boss that shoots a wide Brimstone laser, similar to the one shot by Mega Satan.

Bug!	When there are four Sisters Vis (two pairs, which can be seen in Greed Mode) in the same room, there chance that three of them will act like normal, but the fourth one won't move or attack at all. However, when three are killed, the fourth one will return to normal.

Bug!	Sometimes, a Sisters Vis will become enraged immediately when the other one gets hit instead of getting killed.

Bug!	Sisters Vis can spawn in the bottom center of a Boss Room. If the entrance to the room is from the bottom, entering the room may cause Isaac to immediately take damage.