Hello Katharina.  There are two things happening to your columbine leaves.  The first pest were columbine leafminers.  This is evident in the twisty grayish tan patterns on the leaves.  The big dark spots then follow caused by some fungal disease.  Our wetter than usual summerweather contributes to the extend of the fungal spread on the plant.  Remove all the damaged/dead leaves and dispose of them in your trash not the compost.  If your plant is in a shady spot, you may wish to move it to a place with more sunshine next spring or provide better air circulation to the plant.   I noticed too that your plants have seed pods forming.  Let the pods ripen and disperse seeds on their own. It readily self sows, you should have more plants next year.  Applying insecticides probably does more damage to the beneficial insects population than at interrupting this situation.  Here is an article from Iowa State University Extension on leafminers on columbines.
https://hortnews.extension.iastate.edu/2009/6-3/columbineleafminer.html