For reference, here is part 1 No Iron for your fair-folk maiden? (Part 1)
A brief recap. My fair-folk are weak to all metals, but each metal has their own specific effects. The last question resulted in alkaline metals being mutagenic to them, in addition to being very harmful, just like they are to us.
So, we have the alkaline metals down, now we need to address the radioactive materials. So the question here is this: how can radioactive metals power up my fair-folk while also rapidly killing them?
Also, if anyone has any ideas on how to make the lanthanides affect my fair-folk I would appreciate it. Not necessarily part of the question, but bonus points!