Shadow Magic as spells

[Stormborn]

Shadowcaster from Tome of Magic use Mysteries rather than spells. However, each mystery lists a level and school for determing immunites or vunerabilities v. spells. Can these levels/schools be used to convert the mysteries to arcane spells or are they sufficently different that the levels/schools are only rough equivalnets?

 

[backbeat]

My read was that most Mysteries are higher powered than the arcane equivalant. As examples, the Mage Armor like mystery gives +6 to AC, the Mage Hand like mystery works on magic items, and the light like mystery combines light and darkness into 1.

I would probably consider a mystery +1 lvl when converting to an arcane spell. They are more powerful. This is made up for by the Shadowcaster having split stat casting, and fewer spells per day.