Repair - Selective Database or Collection

Trying to start a large dbpath folder, with 100+ databases.
However, I need just one database.
Is there an easy way for me to do that?
I tried deleting the data files and starting the DB with -repair, this crashed.
Is there a better way to address that ?
Some config that will tell the server to ignore all but specific databases I want to start?

Basically, I’d assume either a config on the mongo.conf file or something. I can manipulate on the wiredTiger metadata (basically, clean up DB pointers or data files pointers)