Wild cards seem to me like they could be fun to use, but I've never even considered using them in any given run since they get hard-countered by 4 different boss blinds (twice as many as card sharp!!), so I've made this extremely small mod (literally 8 lines of code) as an attempt to make them a little more viable.
With this mod, wild cards cannot be debuffed by any boss blinds (including the plant, the pillar, and verdant leaf). (Since the thing's 8 lines of code, they can still be debuffed by the "Double or Nothing" challenge. I'll pretend this was a fully intentional design decision so that the challenge can't be easily cheated.)
-# (Disclaimer: I haven't really done much playtesting with this change yet, so wild cards could either still be pretty useless or be way too powerful now for all I know. It's also undeniable that this buff is a little bit inelegant since wild cards now have two independent positive effects.)
You can download the mod with the hopefully-attached zip file. (Requires Steamodded... not sure which versions it works with, but I'm apparently using 0.9.8.)