Trying to make a complicated enemy

So I'm working on a game where you essentially get chased by an invisible monster over the course of 10 minutes and you have to hide in certain places so it will leave you alone. I know how to make the monster follow the player, and I have an idea of how to make the monster only move when the cameras are being viewed, but I'm still trying to figure out how to make it so running from the monster gets more difficult.

So something like this:

1. 30 seconds or 1 minute in:
2. Monster spawns
3. Slow
4. Waits a bit before going back to find player after player comes out of hiding spot
5. 4 minutes in:
6. Monster gets faster
7. Wait time decreases
8. 1 minute in:
9. Monster gets even faster
10. Will no longer wait before going back to find the player

I played around with the Follow and Pathfinding behaviors but ultimately I couldn't figure it out myself. Especially since I only have 5 events left in my project :')

Also supposedly, part of the game is that you can use security cameras to see the monster so I wanted to make it so that the player switches between a 2d sprite and a 3d shape, and hiding makes the player invisible, but it ends up making the 3d shape visible in the 2d camera until I use the security cams, then it fixes itself. The monster doesn't chase the player as long as they're invisible and overlapping the hiding place.

You can have a global variable that counts up, add 1 every 1 seconds or somethin, then have conditions like GV=240 set the pathfinding speed of the enemy to a higher value. Use a variable also for the enemy wait time and you can lower this at the same time.