This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
鏓 combines 金 (metal) with 悤, which likely contributes the sound. The exact historical development is uncertain.
The left side is metal 金, and the right side 悤 is a complex shape. Without a clear meaning, picture a mysterious metal object with an intricate design.
For ソウ, imagine a soul (ソウ) trapped inside this mysterious metal object: soul -> ソウ.