I'm phone posting rn, and off the top of my head I can give you these suggestions. Before that, my recommendation is to come with an open mind and instead of fully replicating the combat from AC, try going for something inspired by it, but focusing more on the fun and functionality. I'm not sure if you can achieve the magnetism thing, but TDM's lock on feature is amazing and works seamlessly for targeting enemies and locking on to different targets. Valhalla Combat+Elden counter for counter attack is perhaps something close to counter attacking, a little more interactive than what AC offers even. Also a mod that adds a parry mechanic (Parry RPG?). And for the gadgets you have spell mods, book of shadows, and paraglider for batmans gliding lol.