Both the body and the Soul are invincible while the body is returning to the Soul.
The Forgotten will deal ~4-6 times Isaac's damage to enemies that collide with it while it's returning to the Soul.
This item is not in any item pool and is set to be hidden from appearing in any normal scenario. The only way to obtain it is by picking up Birthright as Tainted Forgotten which will give you the item in the consumable slot.
It can, however, activate when using Metronome. This does nothing with most characters, however it will return Tainted Forgotten's body to him if it is activated.
Rerolling Birthright via D4, D100 or similar items will not remove Recall from the consumable slot.
The item cannot be used while the Soul is holding the body or the body is travelling after it has been thrown. Trying to use it will not waste its charge.
Using the item multiple times at once (e.g. by picking up batteries) will make the body float and slowly travel towards the Soul. During this time period, both the body and the Soul are immune to all forms of damage until the body is retrieved. The body will float for a maximum of 5 seconds per charge used unless the Soul comes in contact with it.
The body is still able to perform its normal attack while floating mid-air.
The body won't deal contact damage while floating. Damage is dealt only when the body snaps back to the Soul.
Obtaining Recall on any other character has no effect.
Car Battery: Counts as using the item twice and immediatelly makes the body float mid-air, slowly approaching the Soul, making both of them immune to all forms of damage whilst floating.
Using Genesis will transfer Recall to the default active item slot. If Isaac picks up a different active item, it will not replace Recall even though it will go into Isaac's inventory. Using the new active item is not possible. This essentially prevents Isaac from obtaining any active items.
Using Butter! to drop Recall won't work either. Even though Recall will be dropped on the ground, Isaac will still not be able to use any active items. Not even picking up Recall again will work.