Board Thread:Questions and Answers/@comment-39202248-20190420153917/@comment-37372149-20190427163751

with story mode you can get easy gems as long as you do not use gems to revive under all circumstances. Never do that. If you can't get past a certain point in story mode then wait until you have better units, because it is not really worth it otherwise.

I would recommend doing FNs and Raids to get some good and useful F2P characters. There are some nice characters to obtain in the Permanent quest section on the right in Extra Island.