Friendly Monster?

[Romulator]

You can't exactly make the monster follow you unless you set path nodes where the player walks, and you may need to do some intense scripting to figure out where the player is for the monster to follow. I think however the Kaernk (water monster) may work better for that. And as lothabread said, use the SetSanityDrainDisabled to stop the sanity from lowering. It may or may not stop the screen effects though.

As far as I know, you cannot make a monster attack another on command, as they are not built into the game to do that.