I haven't played Bloodborne yet but I will eventually.
I'm keeping the online component in mind with how I'm ranking this because it is a part of the full experience of the games. Some gamers would intentionally do whatever it took to avoid pvp like play offline or staying in that zombied state. It's a completely different experience fighting invaders constantly while traversing the game world and trying not to die. It's a shame that many gamers who never played demon souls will never get to experience it fully when there was a ton of players online.
Demon's Souls- Probably the most unforgiving of 'em. People could backstab easily. There was no real guide for the game. So it was slow grueling experience to figure out everything. Plus it was the first of it's kind and everything felt new. It was a roller coster ride just fighting the bosses and invaders. It was more difficult overall to obtain the best gear/spells/miracles. It was very easy to mess up a playthrough by killing npc's or missing things like crystal lizards. Every mistake you made, you paid a price for it. The platinum was a pain to get. If someone had a really good weapon, they damned well earned it until some jackass figured out how to duplicate items by exploiting a glitch.
Dark souls- It didn't really reward grinding or farming as much as demon souls did. I didn't like the changes to the spells/miracles and inventory system. I didn't run into a lot of invaders in this one compared to demon's souls. It was just over easier to beat and get the platinum. It was easier to get weapons and gear.
Dark Souls 2- Soul memory destroyed the multiplayer for me. It felt a bit dumbed down/muted for new players.
