Bethany (nicknamed Beth) is an unlockable character added in Antibirth. Any Soul Hearts, Black Hearts, and immortal hearts that Bethany picks up are added to a counter instead of her health bar. This counter can be used as a charge for the Book Of Virtues or other activated collectibles. Each heart picked up increases the counter by 2. She has a chance of dropping a Soul Heart on room clear, separate from the regular room clear drop.
Bethany is unlocked by having any combination of 12 soul, black, or immortal hearts during a run with any character.
Black hearts will deal damage to the entire room when consumed, as if a regular character took damage and a black heart was destroyed.
If Bethany uses 1 black heart counter to charge an item, the black heart's room-damaging effect still takes place. This means that 1 black heart (2 black heart counters) can be used to deal damage twice.
Immortal Hearts provide a white flame orbital when consumed, even if Bethany does not have Book Of Virtues equipped. The orbital grows in size after every cleared room, generating a blue flame if at maximum size.
Using Converter consumes 6 soul heart counters. However, even if the counter has less than 6, Bethany can still use it, allowing her to obtain 12 heart containers easily.
Picking up an item that removes all red hearts containers such as Abaddon will kill Bethany instantly
Bethany starts with angel room spawn chance, so she can have an angel room on the 2nd floor. (It is the Book of Virtues that gives her this benefit)
If Bethany uses a Joker card on the first floor, or is teleported using a Red Chest, she has a chance to be teleported to an angel room (Use the seed TDZ8 ENDA, a Red Chest is in the first floor Curse Room).
Since red hearts cannot be protected, any hit will destroy your chances for a Devil/Angel room, making Goat Head more valuable than ever.
Because Bethany only has red hearts, Blood donation machines can be very dangerous to use unless she has more hearts saved to replenish the lost ones. (Same applies to any damage triggered item, Devil pacts, and the Devil Beggar).
The tears shot by these flames travel through obstacles, allowing you to attack while hidden behind one.
You should think before taking a Devil's deal, since the Book Of Virtues increases the chance of getting an Angel room, even on Floor 2, and a deal will remove this benefit unless you get Act Of Contrition.
Blood Oath will take most of your red hearts at the start of every floor. It is not recommended to take unless you have a very reliable dodge skill or health source.
Dark Bum will take every red heart and convert them to Soul hearts, so you'll sacrifice health in exchange for an item charge.
The "Soul charge" is exclusive from Bethany, not the Book Of Virtues, so you can use the counter on other active items, but items with long charges (for example: The Necronomicon) can drain it very quick (Remember the Book of Virtues only has two charges).
Whore of Babylon only actives on the half of the last heart, meaning that Bethany must be at the very verge of death to benefit from it.
9 Volt will always charge the first bar, allowing you to save hearts from the counter.