The leaves look like the shape of aquilegia, but no flowers?
I'd say it's definitely an aquilegia (columbine). Self seeded seedlings I have in the garden don't flower in at least their first year.
It definitely doesn't look very well!
I agree it looks sick but so does a lot of variegation. I think it's supposed to look like that. Google 'variegated aquilegia' and look at the images
maybe it needs more sun as its in a shady spot.
We have three like that, appeared this year. They will be weeded out along with the other 10 th0usand seedlings.
I don't think it minds a shady spot, I have them in shade. Either it's hungry or they are old leaves and you need to cut them off and let new ones grow. Give it some organic fertiliser anyway.
I think it's a natural variegation. This can occur in many species and is a result of genetic mutation. Sometimes there is still enough photosynthesis going on for the plant to remain healthy, sometimes not and they eventually die. Only time will tell if it's going to be worth keeping. If it flowers, sets seed and any of the resulting seedlings also show variegation, plant breeders may be interested in it.