You know, this scene does look better with the armor. It makes sense as Jack’s been fully corrupted by Chaos, not to mention he’s going rogue against the Lufenians. So like Darth Vader, him wearing the iconic armor makes sense because it’s too late for him as he’s fully gone on to the Dark Side.
I kind of agree, but he doesn't truly become Chaos until he defeats Darkness Manifest, which is not only it's namesake, but also Jack's friends as well.