Arrow keys to move. Tap A to use Vengeful Spirit (powerful spell). Hold A to focus "soul" and regain masks. Press C to use Mothwing Cloak (dash ability). (not recommended for this insanity) Z to jump. X to swing the nail.
The Mantis Lords are going VERY FAST NOW for a mysterious reason. They're projectiles can sometimes duplicate (intentional). It was too hard when they were going light-speed so I made it so that you only take damage 1/3 of of the time. This is what you get when you tweak values in code and mess around. This is very very hard unless this one weird glitch happens. My record is 260.8 seconds. I'm certain you can do better than me.