Book of Virtues: Spawns a pink eraser wisp on the middle ring. The wisp is immune to projectiles. If a non-boss enemy touches the wisp, it is erased and the wisp is destroyed. The wisp cannot erase bosses, regardless of how much health they have left.
My Shadow: Erasing a Charger will prevent all newly created friendly Chargers from spawning, rendering the item useless. The item spawns a normal Charger before changing it to the special My Shadow variant.
Number One: Lowers the Eraser's range drastically, making the item much more difficult to use. Range increases do not negate this.
Sharp Plug: Attempting to recharge the Eraser with the Sharp Plug hurts Isaac for half a heart without recharging the item.
In Antibirth, this item was Single use and wouldn't permanently remove an erased boss from the run.
If this item kills Dogma during its first phase, it will treat the room as a regular room clear, dropping an consumable, but with no doors to walk out of, softlocking the room. However, this will not occur if you erase the television, instead skipping straight to its second phase. If used on the second phase, Isaac will also be stuck in the boss room.
Using this item to erase the chain of The Visage will make the boss unkillable.
Using this item with the Butter! trinket and letting it cycle (e.g playing Tainted Isaac), will cause the item to regain its charge, granting infinite uses.
If used to kill the Mom's Heart leading to Corpse, it will not count it as a kill, preventing progress on the path.