Credit goes to KarmaDog214 for this one:
Spidey Sense--Have 1 skill point for Spidey Sense (this will save energy and more skill points)
Web Warrior--You want to max this out as much as possible for effective damage against Scorpion.
When the fight begins, make sure that you first use Spidey Sense and have enough energy for every time you need to use this (as in right after its effects wear off). Then, start spamming Scorpion with Web Warrior. If you run low on energy, quickly start using melee attacks. For every time he loses 1/5 (or 1/4...Don't remember) of health, a scene will trigger and two buttons will show up on the screen. Make sure you press the two buttons to save Dugan from being crushed. And right after the scene, make sure you activate Spidey Sense, use Web Warrior and repeat, otherwise Dugan is screwed.