everywhere, all over, all around, revolve
徧 centers on the idea of being everywhere or all around, covering a whole area or revolving through it. The given meanings all express this sense of pervasive presence or movement.
徧 combines 彳 (movement) with 扁, which likely contributes the sound and the idea of being flat or spread out, suggesting movement that covers everywhere.
The left side 彳 suggests movement, and the right side 扁 looks like a flat, spread-out object. Picture someone walking everywhere, spreading their presence all around.
For ヘン, imagine a hen wandering everywhere in the yard, covering all around: hen -> ヘン, and the hen's movement makes the scene pervasive.
Sōhen school of tea ceremony