I'm pretty sure Emily has a spark of her own, she is a power of her own same as Katie, Bella should be a magical being, or as what do u classify a werwolf ?
Yeah i think that hammer should outperform Emilys sword, i dont't think her sword is on the same lvl as X or the hammer as they both seem legendary weapons (could be wrong thought).
But with Emilys attack, MC's attack with X and Bellas new toy, thats probably instakill for the most enemies, that being said there is no such thing as overkill.
The only thing is, MC's normal magic (poker) is not really helpfull, it's to weak against foes with 2-3k hp upwards and the dmg is negligible compared to Emilys attack or X. I kinda hoped there would be some kind of atk boost like 1-2% per lvl.