Condemner in your campaign guide, what level are the replacement spells cast at?

Condemner in your campaign guide, what level are the replacement spells cast at? What if attacker can’t naturally cast?At their base level, and do not require the user to be a magic user

— Matthew Mercer (@matthewmercer) September 20, 2017

The wording is a bit odd, so I’m curious. How do you envision the Crossbow working with concentration?The same way concentration works for maintaining a spell. Constitution save when damaged. Like any other Magic item that allows a spell

— Matthew Mercer (@matthewmercer) September 21, 2017