Erica is good with a gun but Shinobu’s speed will nullify that weapon entirely. Erica’s best chance at that point is to use her robot to keep up and I have my doubts that the suit would be able to pull that off either. It’s made more for power than speed and while the attacks would deal a great deal of damage to Shinobu, good luck landing a hit on her. Ultimately this Demon Slayer would prove to be far too agile to go down. Not even Erica’s high amounts of spirit energy can close the gap. Shinobu (Demon Slayer) wins.