In Dishonored 2, what if the playable character you don’t pick could serve as your companion during missions?
Maybe Emily has the capability to summon Corvo, just as Daud summons his Whalers, so that Corvo can distract some guards while she silently sneaks in to assassinate their target.
Maybe Corvo is running low on health or mana or ammo while he’s fighting and Emily is able to toss supplies to him Bioshock Infinite-style with a “Corvo, catch!”
Seriously, though. Just imagine… Kaldwin-Attano Assassination Squad.