Raw Source Abilities
The idea is to not have your source channeled into anything (Like fire, water/ice,earth) magic but rather just have powerful raw source abilities. This could be tied into souls of characters more as well, like being able to forcefully rip the souls out of a living creatures body to negate its resistances for a turn or two. Or possibly consumable bottles of source if you have an empty bottle and consume more. That's all I've really come up with but more creative minds are better suited for this sort of thing but thanks for reading anyhow.