The False King was the most trouble I had on a boss, teleporting is unfair.
I'd offer to help, but I still need to be bored enough to waste a few more hours on the drum trainer.
Not happening.
Comparatively speaking it's pretty hard. Although some of that depends on tendencies and whether or not you're searching out optional segments of the game. Bonus points if said optional segments happen to be in NG+ where everything doubles in stats.
Actually it'd be more grinding, since when you play online players can drop by to kill you. The blue phantoms can be useful, but they don't typically make the game that much easier (and considering you can only summon them when you have a body, they're of limited practical usefulness).
The only comparable games I can think of, that I've played, are Morrowind and Oblivion, and only in play style. Even though I chose wizard as my class, I ended up using a bow and scimitar more often than spells, I'm terrible at targeting.