What is strength? The ability to exert force. What does force do? Cause or prevent movement. I’d say that’s a strong argument for Space, or even Breath. What are the canonical ties to Rage and Void?

Motion as Force could definitely work, and Space, yeah of course. Rage though, going Berserker, blind anger, it seems closely related. Void relating to Physicality where Light relates to Ideas makes it tie with Strength- Paired with the ‘Lack’, as in, Lack of Weapon as well, both Equius and Roxy have Fistkind as one of their Specibi, and the whole Indigo caste, Void-bound, seems to be tied to physical strength.