change, strange
變 centers on transformation and deviation from the norm: change, alteration, or something strange and unusual.
變 is the traditional form of 変. It combines 䜌 (a phonetic component suggesting continuity or entanglement) with 攵 (a hand holding a stick, implying action), together expressing the idea of altering or changing something.
The top 䜌 looks like tangled threads (言 and 糸), and the bottom 攵 is a hand with a stick. Imagine using a stick to untangle and rearrange the threads—changing their form into something new and strange.
For ヘン, picture a hen pecking at the tangled threads and changing their arrangement: hen -> ヘン, and the hen's actions transform the mess.