From what I've gathered while playing, it forces you to angel deals and any black hearts you've gathered will be lost upon entering the angel room (to compensate for this, any empty red heart containers you have will be healed)

The black hearts that you've lost will be converted into angel room items (1 per 3 black hearts)

I didn't experience the effect you described yet...

New Penance guarantees an angel deal room if u have atleast 1 black heart I believe. Soul hearts turn into black hearts. When you get hit, if you have any black hearts, you lose them all and it turns into a demon who attacks you until the room is over. The first angel deal costs 1 black heart, the second one 2 hears, the third one 3 hearts, ect and i think it caps at a certain price of hearts like 5 or something. I havent studied it for the wiki yet but this is what i've been told/experienced it doing

@Grynn that sounds really cool but my Angel Rooms were always empty. I only had the angel in the room which would heal you

Yeah, you have to touch the angel statue

It's a free mod. If you don't like it, don't use it. Honestly, I don't even know why people leave comments if they're not going to praise the author. It's not like anyone's twisting your arm and making you play it. Aren't you grateful that someone made all of this content for free?

(At least, that seemed to be your stance in the main comments, 1up.)

He's just confused, dude. Most people are after such a large rework to a character's main gimmick. And even if he didn't like it, he has every right to say so, in fact he should if he ever wants the experience to be better. Bug reports and constructive criticism are important.

Where did I say I didn't like it? I like the mod I just didn't understand what the new penance did. I prefer the old penance but thats just one item. I like the mod, hate the new penance. Can I not have an opinion or what?

I don’t think 1up gave the impression that he didn’t like the mod at all. The mod just came out and the wiki isn’t updated yet, so people are gonna have questions. Having questions =\= hating the mod. Having a preference of old item or new item =\= hating the mod.

It appears that if it hits you enough the demon will disappear without giving the hearts back. Anyone able to confirm this?

yea sometimes my demon just disappeared with me losing the hard

Everytime the demon hits you, you lose a half of the black hearts you lost. So if you get hit enough and lose all the black hearts, the demon won't be a thing anymore