I find the array of abilities available to the three protagonists really interesting. Blink, for example. During Dishonored, Corvo's Blink is considerably weaker than Daud's, which makes sense; Daud's been using black magic for nearly twenty years and Corvo's had his magical abilities for literal days, even by the final mission. Emily's transversal abilities are weaker still, acting as more of a grappling hook than actual teleportation.
Bend Time is another good point. Daud's Bend Time abilities are incredibly powerful, stopping time completely for twenty, thirty seconds, while Corvo's will stop time for about eight seconds fully upgraded. The power isn't even available for Emily to purchase.
By 1852, Corvo's power set has caught up, yes, but he's been using them for fifteen years at this point. Of course he'd be more powerful.
If Corvo's/Daud's power sets had color schemes, they'd be black-blue/black-gray. Industrial. Solid. Right-angle. Magic of the Outsider (which sounds ridiculous--everything is magic of the Outsider.) But Emily's would be riotous violet. Because she enjoys using her magic. Corvo sees it as just another tool to get what he needs to do done, and Daud has employed it for profit. They're both using magic as a tool. Emily's interest in the Void and its inhabitant has imbued her magic with a perverse life of sorts. This is why it's slicker, smoother. Interacting more with the actual humans she's affecting rather than the environment around them. Domino. Far Reach. Doppelganger. As opposed to Bend Time, or Devouring Swarm, or even Pull.
Maybe it's a manifestation of her guilt about being such a removed Empress. Now that her throne's been stolen from under her, she has to interact with her citizens head on. And maybe her magic is an extention of that.