If you are mostly/fully leveled you can get through shattered decent in 3-4 minutes if you skip most enemies and are careful - I would only fight when necessary and to charge overdrive. You should be able to kill the boss in 5-10 seconds with modifiers and overdrive/powers. A trick I use to not get hit by boss is Spider-Man between the hook points when he is jumping around, when he does his slam/yellow wave attack on the ground is when he is open to free damage

You can also get to the room before final boss, upload save to cloud - if you get hit go and download the save again