Can you convert a CDB created with US7ASCII characterset to AL32UTF8 characterset?

I'm in the process of upgrading our 11.2.0.4 EBS R12.1.3 database to 19c but the CDB got created with the NLS_CHARACTERSET = US7ASCII even though I selected "Use Unicode (AL32UTF8)" on the specify configuration options screen of the dbca. Maybe my mistake was the National character set on that same screen was set to AL16UTF16, so the NLS_NCHAR_CHARACTERSET of the CDB is AL16UTF16. My EBS 11.2.0.4 database (EBS2D) is nls_characterset AL32UTF8, so now I cannot convert it to a pdb because the character set doesn't match the CDB character set.

I tried running DMU, but it never opens. I tried using dbca to delete the CDB, but it wants to delete the EBS2D database (which would be the PDB). I was going to create a new CDB, but I don't have enough FRA.