About time we had a villain in TLR worth giving a damn about. Nemesis is exactly the kind of spice that the series needed after a dry spell of weak antagonists and lack of real danger. Her very presence oozes both sexiness and intimidation, and her mischievous personality is the perfect counterbalance to Momo's shenanigans. I'd love to see a re-done version of the color page with Yami and Lala featuring these two when they inevitably face off.
Good to see Oshizu's still on guard against Mea, since their previous encounter isn't something that would be smoothed over so quickly. Mikan's also on guard against Mea, but for much dirtier reasons
It's uncertain whether Nemesis will be integrated into the harem. Honestly, I'd prefer she stay out of it. She's a much better fit on the outside trying to stir things up, plus the whole "Darkness" subplot might make her too sinister for the cast to forgive. Whatever happens, I can easily say that her arrival is a breath of fresh air, and I can't wait to see what she does next.
I also can't wait for the flood of doujins involving her 