Grrr.
So I'm back on Judas again, who's refreshingly powerful after playing the others. For the first time I'm finding the game generally easy, not by an overpowered combo or anything. I get the right upgrades, find Transendence early on which is useful, crank up fire rate to maximum and use Book of Belial frequently. End up with maxed out coins, loads of bombs and more keys than I could ever use.
Wander nonchalantly through the Womb, get a really easy Blastocyst variant for Boss 1, almost lose my health a couple of times but get lucky with slot machines and Little C.H.A.D. Then, just outside the boss room, I get taken down to four hearts.
"Should I go back and look for more? I've blown up all the slot machines but I could probably find another, I've got 99 coins* and enough damage output that I'd still make a net health gain."
I'm at the last room of getting two wins in a row for the first time ever.
"Nah. It'll be fine."
Do the tried-and-tested Bomb 'n' Strafe method, get Mom's Heart down to maybe a quarter of her health, then get hit by a stray blood bomb and die. I didn't even get a chance to use Whore of Babylon.
The real kicker? I just remembered I had The Fool card. I could have got myself out of there when my health got low, but I forgot.
*But the bitch ain't one