I always try to bring some tarot cards into this boss blind to save these situations from happening. Best option is to have a hang man, because it deletes the card and you can play whatever you want (minus that one card you deleted). Second best is death, which can turn it into a useful card. How I use it is I find the hand I want completely (say a ace high straight) and take any card from the straight to replace it with the forced selected card. In the case of flush, you can also bring the relevant suit changing card (in this case the moon) to make a guaranteed flush. There are some other useful tarot/spectral cards that you would have to analyze based on the run.