My first thought was Nightshade, but @DEClimax beat me too it. I’d say that’s the best option.
Other ideas include:
Corpse Lily (or C. Lilly, if you prefer)
Daphne
Hemlock
Oleander
Y. Jasmine (or Yellow Jasmine if you prefer)
Belladonna
Datura
Larkspur
I think that there are some cool options in there as well. I agree that simply calling her Shadow Orchid or Shorchid is a bit more on the “been there done that” side. Same goes for the idea of simply taking Orchid, giving her blue skin and a skull mask and maybe a chain belt or something. Redundant City, no doubt.
I get the feeling that this is what people are picturing though and I don’t really see that as a slam dunk. I’d like to think that they could come up with some creative ideas that give Orchid a similar concept, but also does it in an entirely unique way.
Personally, I’ll take any variation on Orchid here over a man shark hybrid. As much as I have faith in MS / IG, the idea just sounds fundamentally flawed to me. Totally down for a sea creature or Cthulhu or a gorgon, etc. Not a street shark.
To me, this looks insanely cool:
This would be amazing for a gorgon!
But this?
Granted… I can see why people would like it. But to me it looks like a mythical creature on a low tier Scyfy movie. I get that KI has many influences in pop culture. Not sure I feel like Sharknado needs to be one of them.
I mean, why not a half squid half man or a half wasp half man or a half corgi half man. I dunno, for all the people saying Shorchid isn’t unique, I’m surprised to hear people feel that this is. I mean… Just because it’s unique to KI doesn’t me it’s a unique (or compelling) idea. I’d also say the opposite can be true as well.
That’s not to say “unique” has to be the deciding factor. A monk, a spy, a Native American, a robot, s boxer… KI has plenty of ideas culled from other places, but that’s kinda the point, right? KI takes those things, those cool influences, and makes it insanely fun, fresh, and yes, unique.
My only feeling is, with a man shark, that’s just not a cool influence, so I don’t personally dig the starting point. I like Orchid. I like Shadow Jago or the idea of a corrupted hero. These are all things I can work with or envision with an open mind and for me, that’s the difference.
However, I will say this. If they do make a man shark, I’ll be happy for you awesome people that want him, and I’ll hope like heck that MS / IG does right by the idea, for your sake and mine, so I can learn to love the idea as much as you do. It’s not my choice, but here’s hoping most of us are happy with whatever they choose to do! 
