1A myriad of changes; constantly changing or presenting endless variety (yojijukugo, can be used with 'suru').
千変万化の表情を見せる彼の演技には目が離せない。
You can't take your eyes off his acting, which shows an ever-changing array of expressions.
自然の景色は季節ごとに千変万化する。
Natural scenery changes endlessly with the seasons.
彼女の作風は千変万化で、毎回違った作品を見せてくれる。
Her style is endlessly varied; she shows different works each time.