I found the issue, and it is an issue with the stock code, or more specifically the install.sql file. The fname values of the blessedstrike and stoneskin spells is bonusattack and bonusdefense, respectively.
The values should be blessedstrike and stoneskin. Therefore, the spell is looking for a function names bonusdefense or bonusattack in the spells.php file. None exists, so no spell is cast.
Here is the fix. Of course, the table prefix needs to be changed if you have anything but sx_.
## Run these SQL Queries ##
update sx_spells set fname = 'stoneskin' where fname = 'bonusdefense'; update sx_spells set fname = 'blessedstrike' where fname = 'bonusattack';
