Nah, they're pretty much all easy no exception, I've died a ton in these games but I never ever died against a boss, not a single time.
Levels are hard, bosses around.
I mean hell I did Dark Souls as a level 1 Pyromancer without ever changing my equipment. The problem's just that their attack patterns are too predictable.
Like the Spider in Demon Soul, it was always the same thing, run in zigzag towards her and roll to dodge her web/fire, when close just block until she uses that attack that leaves her stunned, whack a ton on her, sprint back to dodge her inferno attack. Rinse and repeat. Always the same thing the whole fight, the Tower Giant is just about running in circles around him, there's almost no risk. Queelag in Dark Souls is just about running everywhere until she does that long fire spewing attack that leaves her open for at least 3-4 light hits, etc.
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