Savage Worlds, No Power Points, Casting modifier

[Mask_of_winter]

I'm building this extension and module for Solomon Kane. I'd like to make some changes to the character sheet and power entries to change Power Points to a Casting Modifier instead. How do I do that?

Easiest way I thought of doing this would be to create new power entries. I'm not sure if the field could take a negative value though.

Any advice or pointers would be much appreciated.

Thanks!