Different power system. In dark souls the gods are in decay but in bloodborne you fight great ones on their home turf. The lord of hollows ending does however elevate the ashen one to the same level as the reborn hunter
There are identical hollow spaces in the flat of each arm of the bow when the blade transforms. I think they the form a container when the blade is together, where the bow mechanism folds into in sword mode. I would guess the hilt and cross guard form part of that mechanism when the sword transforms.
Never seen this discussed anywhere, but the floral motifs on the hilt and along the blade are the same as on the Chikage, Maria's Set and the Knight's Set, suggesting the Bowblade, too, was made in Cainhurst. Which makes sense from a lore perspective. Vilebloods used blood weapons, and during Simon's time they weren't at odds with the Healing Church yet. I love this game.
Actually the design is relatively similar to a shovel type weapon, or the ancient Celtic Falcata though the end of the blade is too thin to cut with thr axe momentum of the celtic sword... anyway, all curved blades are designed for cutting flesh, so which way its facing isn't as important as user skill