The code for generating damage / healing / etc. breakdowns should not be in the SingleEncounterView.xaml.cs file.
All of this should be in a different file. Most likely this should be part of the EncounterInfo class, or an extension for it.
Any parameters such as which player or mode is selected should be used as a parameter for the method.
I generally consider this done now.
Any major Breakdown generation is handled by the EncounterInfo class now. The SingleEncounterView now only does some final touch up to make the data presentable.
The code for generating damage / healing / etc. breakdowns should not be in the SingleEncounterView.xaml.cs file. All of this should be in a different file. Most likely this should be part of the EncounterInfo class, or an extension for it. Any parameters such as which player or mode is selected should be used as a parameter for the method.