積み重ねるとパワーアップする模様
https://image.itmedia.co.jp/news/articles/2205/25/l_yu_volterra1.jpg
https://image.itmedia.co.jp/news/articles/2205/25/l_yu_volterra3.jpg
https://image.itmedia.co.jp/news/articles/2205/25/l_yu_volterra2.jpg
https://www.youtube.com/watch?v=yICVNta8jMU
https://www.itmedia.co.jp/news/articles/2205/25/news073.html