I think your cory death are from the ich ×.. they don't always do well with it.
I don't think.your ram has ich. Its looking alot like early stages of lymphocystis. If so the only thing that will help is time as its viral. It can take months to heal but the fish will always be a carrier.
I could be wrong.. and could be ich but if its lymphocystis it will probably start showing as clumps on the fins. I would definitely not add discus until you know. Rams seem particularly prone to it.
https://edis.ifas.ufl.edu/publication/FA181
Search " lymphocystis ram cichlids" images.
Al