Who animated which transformation sequence in Symphogear XV?
According to Anime Staff Database Wiki (Japanese), known transformation scene animator(s) (変身原画) per episode:


Hibiki: Yoshitake Nakakoji (中小路佳毅) (tweet)


  シンフォギア1話　響変身バンクの原画をやらせていただきました。
  
  Symphogear ep. 1, I was allowed to do Hibiki's transformation scene.

Kirika: Yoshiyuki Okubo (大久保義之)
Shirabe &amp; Chris:


Kouki Shikiji (式地幸喜)
Yousuke Kabashima (椛島洋介)

Maria: Hanyu (ハニュー): 
Tsubasa: Hiroyuki Takashima (髙嶋宏之)
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Elfnein/Carol: Shota Sannomiya (三宮昌太)
Miku: Kousuke Yoshida (吉田亘良)
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