This is just my opinion, but if you read the lore, it doesn't look anymore original than that. It's all the Spiderman "With great power comes responsibility" and he is now a good guy cause of that.
Now, the built to destroy but has feelings thing is great, it's the best part, it's what makes Zac, Zac (Despite how cheesy the last sentence is "Originally built to destroy, he now protects the innocent and the helpless")
The point is, and this is the same point i argue with the new Leona, is that people are not just "good" for the sake of story. Things happen to push people towards a goal, or a certain aspect of their life. Why would Zac care about life, if he hasn't experienced the horror of death? All he ever was taught was the "Spiderman" lesson, but Peter Parker had to go through the death of his Uncle to realize what that meant.
(and yeah, my parents are dead thing is whatever, but I've seen plenty of "dead parent" characters in DnD that aren't complete edgelords, and have expanded into great characters)