I opened a mega spectral pack with a 6-card hand and a hanged man in inventory.
Immolating the hand down to 1-card in hand did not allow Incantation to be used "destroy random card in hand to create xxx" - as 1 in 1 random is not really random I imagine - but that is inconsistent with other spectral cards like "add polychrome to a random joker in hand and destroy all others" - which can be used when only owning 1 joker.
Then, when I used the hanged man to destroy the last card in hand, going to 0 cards in hand while in booster selection, it kinda soft-locked the game. I could no longer use any spectral cards and I couldn't even "skip"!
I did fix that soft-lock by exiting out, and continuing the run, as it rewinded me to the opening of the spectral pack.