[@Banana]: Basically, what BC said. I have two main problems with your character.

1. No matter how I think about it, I don't think the helicopter tentacles are feasible at all. For starters, they come out of Grover's back arranged in a vertical fashion, while helicopter rotors are horizontal; he'd have to awkwardly bend his whole upper body 90 degrees forward if he wants to have any chance of flying. And then there's the matter of freely rotating joints, which might've been somewhat difficult to install. Finally, each helicopter rotor blade is thin and lightweight, not at all like thick cybernetic tentacles; the tentacles have too much mass to simply transform into helicopter rotors. Overall, as BC said, it's honestly much, much easier to just give your guy a jetpack if he wants to fly, and there's no real reason why the scientists didn't just do that instead of trying to make the tentacles work as helicopter rotors.

2. There's no reason why the scientists would just let Grover go free after finishing the experiments, since he's now an individual empowered with dangerous new abilities. At the very least, they'd want to keep an eye on him, if not outright have him serve in their military and what not. Maybe one of the other test subjects went berserk and destroyed the whole facility, allowing Grover to slip away in the confusion; he could've then laid low for a while as said in the profile. Or you could think of something else; there just has to be [i]some[/i] reason why he got free after the experiment.

3. Didn't we go over how severely underpowered an M1911 would be in this day and age? The standard army pistol nowadays would be some kind of miniature railgun with significantly more power than modern pistols, or maybe even a plasma blaster. Not a pistol that would almost certainly fail to penetrate even decently well-armored cyborgs and chimeras.