The Souls community is as unique as the games it worships. I feel the bond is so strong due to the reputation of the series we play and die in over and over again (note how I said we, yes I definitely consider myself part of the community). There is something compelling about being part of a group that takes pride in beating some of the most technically challenging games ever made.
Like other communities, Souls has several branches that make up its fan base. The most influential two, in my opinion, are the speedrunners and the lore content creators.
The speedrunners utilise the streaming capabilities of Twitch to broadcast their insane runs to the world. Elajjaz is one of the most high profile personalities who blitzes through the Souls games and has a large following on Twitch and YouTube. The insane feats they can accomplish attract more gamers to the franchise which helps boost its popularity.
The lore content creators are arguably even more incredible. They have the painstaking job of sifting through item descriptions and character dialogue to uncover the secrets of each game's wider and deeper story. The work of people like VaatiVidya, EpicNameBro and SunlightBlade helps you to understand and immerse yourself in the extremely intricate and complicated worlds of each game.
When considering the games themselves, co-op is clearly an integral part of the series. There are entire covenants that are devoted to jolly co-operation. The Sunbros, i.e. Warriors of Sunlight (Dark Souls) or Heirs of the Sun (Dark Souls 2), are the most obvious and well renowned, but you also have the Princess Guard (DS) and Blue Sentinels (DS2) too. The challenging nature of the boss fights encourages co-operative play with others to overcome mutual obstacles together, rewarding players for doing so.
There is of course a notorious PvP element as well and fights between players are generally hard fought. The vast majority enjoy it as part of the game and don't whine when killed by an invader. There is always the option to play in offline mode, to prevent online invasions as well as friendly co-operation, for those who want to experience a purely solo, PvE playthrough.
I could easily go on about the fantastic temperament of the Souls community, but for the sake of your sanity I will not. Just know that it always welcomes players with open arms. Whining about the difficulty is not accepted, however, and doing so will simply result in our motto being shouted aloud..."GIT GUD AND PRAISE THE SUN!"