I think he used the fact that he intended to "help" others as an excuse to power trip!
One of those "You don't get it, but I'm doing this for your own good" type of situations. Responsibility involves self-restraint, and seeing all sides. What he did was the opposite of responsible.
And while I don't think he power tripped on the same level as Winnie- I do think she was the catalyst, giving him the permission he needed to do what he wanted. Rayek did hold himself back, i think, before- because he knew others wouldn't support him if he simply did what he wanted. But then, suddenly, here's Winnie saying "their minds are too small" and "act on the greater good- that's all that matters," even "you're above everybody else, Lord!"
I have the sense, she voiced thoughts that were in the back of Rayek's mind all along- hence opening the door for him to ignore his own compunctions.
Hmmm. Anyone want to settle this?