Most of it is here.
After seemingly being killed at the end of Just Cause 3, he somehow returned, like a ghost. He had actually activated a portable Bavarium shield that had been made specially for him for his fight with the Son of Medici.
He then lived in disguise for a while, hiding his right eye, as it had been shot out and replaced with some terminator-style eye.
Events of Cold Blood Vol 2.5 Edit
In Cold Blood Vol 2.5, he returns and tries to retake Medici using a rebellion made of old D.R.M soldiers still loyal to his cause. He, of course, fails at doing this and actually dies for real this time