Regarding Feral Magic, in "Sneaking Suspicions", they discovered Feral Magic during the tests. So there's the hint that Feral Magic comes from "Test Soil Samples" and "Test Boar Tusks". But the drops are not guaranteed so you may need to go through the test a few times!
Thanks PikaSquirrel that explains the issue then
I finished this step now I am working on those scary plants lol