the slow movement speed of the terminator armor combined with some minor UI stuff to make it look like you're in a hulking exoskeleton could make it atmospheric as fuck, having some death animation of the suit being breached with screeching metal sounds could make it pretty nice as well, satisfying sounds for it is as important as cool visuals, you could technically skimp on the quality of visuals by trying to UI it with hue that masks the lower quality graphs with some green blurry outlines or something to make it more immersive like you're looking at some screen showing you combat data