How to get progress?

After beating mom's heart you may notice the devil or angel deal apear but instead of items you got the trapdoor jump inside and beat the satan or isaac 5 times to unlock polaroid or negative

then when you take negative and beat satan then you go to dark room where you can then beat lamb, same with polaroid and isaac.

After beating lamb or ??? if you go to an angel deal and try to bomb the statue you gonna spawn a boss angel after beating him you gonna get key piece 1 or 2, you need them both to progress any further. When you go to dark room or chest in spawn you gonna find a giant golden door
this is where you need key pieces, after geting here with full key the door will open you can fight one of the final bosses!

After killing mom's heart 10 times you gonna unlock the blue womb.
To get there you need to kill mom's heart faster than 30 min ( or you can just use mega bean in repetance+ or mom mega) after that a hole will apear.
There you will find hush, a another boss.

hush
After defeating him for the first time you gonna unlock the void where you can find another boss
delirium

After beating hush for 3 times you can unlock an alternate path.
1. In downpour you can find a white fire

touch it and you will became lost for some time. Walk inside the mirror while you still lost and you transfer in mirror dimension there you need to walk in treasure room to grab knife piece 1
2. in mines find all yellow buttons scatered around the map and press it. eventually you find room with rails and cart, after last 3 button jump in it and find knife piece 2 and run from mom's shadow
3. in mausoleum beat mother and shot your knife at the red door that appeard

then kill mom's heart and go in the corpse there you gonna meet the mother

After beating the real mother for the first time you gonna unlock the strange door.
On the floor with standart mother you find this door in your spawn room

find the marked skull

and blow it up, then you get the fool card beat mother and grab polaroid or negative and use the fool card.
Then put it in the strange door and then go to boss room and grab dad's note and crawl back up all the floors and then meet dogma and beast.

dogma

beast

Thanks for reading this guide make sure to like it, hope you beat every single one of this bosses!