It's ok to not explain everything. Not every villian needs an origin story. Not every MacGuffin needs it's logic laid out. Not every magic system needs a complex rule set.
People may ask for the details, you might feel pressured to get everything perfect and right, but remember fans thrive on imperfect media. Questions and what-ifs lead to fan theories and fanfic and fascination.
You're not writing an encyclopedia. You're writing fiction. Trust yourself and trust your reader.














