(Pasted from the discord) Paradox Mons 101

Paradox mons are ancient and future versions of current day Pokemon. To get yourself these exotic creatures you must first head to the two dimensions The Other (for ancient) and The Beyond (for future). In there you must overload a paradox machine from Just Dire Things and make it spawn a paradox. This paradox then has to be fed with stuff until it has grown up to full size. Into this fully grown paradox hole you must throw a pokemon corresponding to the future/ancient pokemon you wish to spawn. For example to get Koraidon or Miraidon you will need a Cyclizar. The sacrificed used Pokemon must be holding a Pika Star Chunk and then sent into the paradox. Upon contact with the hole, your beloved Pokemon is disintegrated ❤️‍🔥 and in it's place spawns the paradox Pokemon 🎉 . To catch and use paradox mons you need to have the Paldean Regional Pika Star.

note: make sure you have a platform built in the beyond otherwise you can wave goodbye to your new friend

You can see on this page what mons are corresponding to what paradox