Is this the one Silver Zaps during the battle?

no not even the same species

I keep imagining him sounding like lenny from all the cartoons.

If he grabs one of the minions, I'd expect him say something like "And I will love him and pet him and call him my friiiiiiend"

I kind of see him as goofy but not so much "special."

Maybe as a callback to the cartoons though. He looks like the kind of person that would do that as a joke.

Hmmm, from the pictures alone I'm guessing he's a commonblood, fairly easygoing, probably as laid back as you can be in a military outfit, but still fairly pleasant enough to be around that most of the crew don't really mind. He's a simple man, but not simple-minded. Far from it, in fact; he could probably get a doctorate in an Earth university no problem, but he doesn't have that outward drive to really care about certifications and fancy pieces of paper. He can and does take things seriously, but he hardly ever appears serious, which causes some friction with others, especially his superiors. If he does have a flaw, though, it's that he doesn't have any patience for people who do things unnecessarily if an easier way can be had. To me, the upper right picture is him saying, quite bluntly, "Seriously? You want to test twenty different materials under at least seventy different variables? I could just derive the right equations in about six hours so we only have to do two days of experiments, saving us a lot of time and resources. Idiot." Thus, he doesn't like politics and doesn't care for playing games because that's how things have been done. Doesn't really appreciate any social differences between Highbloods and commonbloods. He doesn't mind taking the scenic route occasionally and stopping to smell the roses, though. Likes working with Silver, as he's a good scientist, but he does think that his boss needlessly frets over inconsequential things at times, which Marcus finds a bit annoying. Not much of an empath (roughly average for a typical Darnathi), but he knows a thing or two about how people tick because he's observant and a good listener.

Just my first impressions, largely unfiltered. I really like how expressive he is.

Spot on also gentle giant he doesn't use his brawn to hurt people just pokes them roughly to get them to stop hurting or teasing him

What, really? Dang, you managed to pack a lot of nuance into those three bust shots.