Going by this tweet https://twitter.com/aesuck/status/1368121782679396355 , there were 3 people that worked on this OP
Toshio Mori,Yoshinori Kanemori and Yoshinobu Inano
The explosions/fire in this scene remind me of the ones in this post https://www.sakugabooru.com/post/show/150672 , in that episode Toshio Mori was the AD and did key animation, also the very unique Devil Beam at the beginning of the scene only is so when Mori was the AD
So I think this was done by him