1: No one deserves to die everyone every can have redemption.
2: Villain commiting the most atrocious crimes and are allowed free just because they got a beating.
3: A hero becoming friends with the most evil and vile villains.
4: An ordinary norm suddenly becoming a chick magnet with little to no efforts.
5: Main characters suddenly switching between personalities around the same people.
6: Zero side character development.
7: Stupid plot made to suit stupid characters who end up making the somewhat stupid MC seem smart with every normal thing he does.
If I see any of this in your story then just be certain I won't be reading it and I won't be leaving without a review either.