Isn't it calling Ben a religious fanatic a bit too extreme? I do think he's at least a bit compromised with bringing some peace to the Galaxy? Considering his speech to Rey he did think by himself about bringing some degree of order and peace even if in the wrong way.
When I mention religious fanaticism, I’m referring to Adam Driver’s comments about how he plays the character:
Driver says that he sees Ren as more of a religious fanatic than a villain in the traditional sense. “When they think of their actions as morally justified,” Driver told us, “it makes them dangerous and unpredictable. There’s no level they won’t go to to accomplish what they’re after. I never thought of the character as an evil person.”
There’s also the imagery of him praying to the Vader helmet in his room, and his fervent, brainwashed-sounding comments - “The Supreme Leader is wise.” “The Supreme Leader senses it.” “It is your teachings that make me strong, Supreme Leader.” “I’ve given everything I have to you.” Snoke had been in his head since he was a child. I’ve always personally interpreted Ben as a bit brainwashed/fanatical in motivation, and I saw his killing Snoke as Ben striking at not only his abuser, but also his ‘all-powerful’ religious cult leader. Of course, this is just my interpretation.