You're on-target with the Shiva line. I found this on a Hindu website and it's scary how close it comes to describing the characters we're discussing: "Shiva is responsible for change both in the form of death and destruction and in the positive sense of destroying the ego, the false identification with the form. This also includes the shedding of old habits and attachments ... Shiva represents the most essential goodness." Gives an interesting slant on the character and what his future might be.

There's a very famous quote from the Bhagavad Gita by Robert Oppenheimer, after he saw the first atomic bomb detonated at Trinity/Alamagordo: "Now I am become Death (Shiva), destroyer of worlds". Another thing that struck me was that a character other than the protagonist is the one who got the voiceover monologue. I can't think of another instance quite like this one.

Reminds me of that observation from Joseph Campbell about one of the messages of myths: "Destruction before creation." This is also echoed in Jung as the individuation process is about breaking down the psyche systems we have in place that block us from accessing deeper and often darker parts of our self, eventually leading to a more authentic way of being. The Shiva line is also interesting to use as a lens through which to look at Arthur as a prophet 'crying in the wilderness.' He has broken free of the system and now stands outside and in judgement of it. His intention is to give it a mortal blow. But systems accrue power over time [The Powers That Be], thus they destroy Arthur. To round out this imagery, Arthur's destruction can be seen as a key cog in Michael's resurrection as a human being, an individual.

For me, the "I am Shiva..." line is basically Peter Finch's line from Network: "I'm as mad as hell, and I'm not going to take it anymore.", except that there's the implied scorched earth threat that Arthur's going to do something about it, and take everybody else down with him, if he has to.