Many try to diminish my doings. The cause of a new world order. I bring with me death, famine, and disease. To the benefit of a few and the detriment of the majority. I destroyed worlds. What am I?

I am worn by a man who insists I am he Yet I have no stable form I shift and flow through the calm and the storm I am a mere pattern, yet the wicked curse my design I work to bring down he who declares 'Look on my works, ye Mighty, and despair!'

A salad with no tomatoes, but still run red. Stabbed in the back by the one called friend.

To the superstitious, I'm worse than a shot of caffeine, But stop by a generous bakery and you might find luck unforeseen. I’ve deleted entire floors with my ominous sheen, Yet I'm just a number - what do YOU think I mean?

One dressed in black, a modern tribe of gloom and song; the other sacked Rome in four hundred years before Christ, forging a kingdom in Iberia. Same ancient name they share, who are these shadowed cousins?