>>151240249
Also I have an inkling this is why Rosie shuts him down for so long. She's still more powerful than him, but starts to worry about how much power he's accumulating even killing minor overlords on his out-the-gate rampage.

The rest is in large part my own headcanon because I'm extrapolating to fill in a lot of gaps so don't quote me on it. But I think Alastor's 'Plan A' after making the deal with Rosie was to show up in Hell and start offing minor overlords for this reason, due to his prior knowledge of how Hell works. When Rosie shut him down he had to resort to a less obvious 'Plan B' and more skullduggery, but he's even more confident he will prevail because his power level got significantly closer to hers before that happened. Like he expected 'Plan A' to get nixed but he gained an advantage just by trying it, and somehow knew Rosie wouldn't do shit in retaliation, (probably because she still needs him for her own task, which a little increase in power might help with).

I'm not sure it's exactly that, but I think it's going to be something like that, and haven't heard any disconfirming details, (which I have been specially looking out for).