MrRetsej |
The Sure Casting spell increases your caster level by 5 for overcoming SR on the next spell you cast, is on the Witch list, is a 1st level spell and there is no stipulation I can see by RAW that you couldn't apply the +5 CL to a Magus spell provided it is the next spell you cast. Plus, it stacks with Dweomer's Essence.
So you would cast Sure Casting, and then use the Dweomer's Essence as a component on the spell you want to cast next round for a +10 CL vs SR. This would stack with any other means of overcoming SR.