Thank you Anderson for pointing me in the right direction.
To follow-up: All subjects have complete data. I am interested in the group effect and condition effect.
Since this set up does not allow to look at the group effect, I need to 1) get 4 gfeats (experimental and control feats for HC, and experimental and control feats for patients) where I would model the means of each subject, 2) perform experimental + control analysis for each group and 3) compare the outputs (i.e. HC vs patients).
Am I understanding this correctly?