Complex sentence: This shows a dangling chain which he pulls all the way and floor slides open to reveal a giant floor with the same inscription as Mizuki's own cursed seal and prepares a formula which he believes will bring him great power.
Split into simpler sentences: This shows a dangling chain which he pulls all the way. The floor slides open to reveal a giant floor with the same inscription as Mizuki's own cursed seal and prepares a formula which he believes will bring him great power.