A guide to what the corrupted version of each upgrade does.
Shield -> Mi-Go Shield
Automatically counter-attacks after taking a certain amount of damage.
Gun -> Armageddon
Fires a steady stream, which gradually depletes Energy.
Leaping Device -> Z'Toggua's Wings
Enables a "glide" after a double-jump.
Charge Attack -> Ghatanothoa's Strength
Makes attack stronger, with two levels of charge.
Wall Run -> Atlach-Nacha's Grip
Wall run from a jump, and stop anywhere along the wall.
Propulsion Engine -> Azathoth's Breath
Air-dash is replaced with an omni-directional teleport, with the same range but slightly longer cooldown.
Grappling Hook -> Eldritch Pull
Press trigger again after grappling to jump and create a small explosion that damages enemies.