I have a few issues with this, the premise is dumb. Like really dumb it makes no sense the MC would be punished so severely for poor story writing. It's not like it resulted in people dying or anything just some wasted time, hell he didn't even write that many stories.
Secondly why would you reincarnate him as someone designed to die before the story starts? Also if he changes events outcomes then he won't know how the story plays out cause it'll be different. Also also the MC is dumb as said above things are happening around him like death and explosions and instead of moving he's just mentally thinking and not moving at the same time.
Another dumb thing is would he even know the layout of the castle? His dex is low rated so how would he even outrun the enemy?