Lusamine is the president of the Aether foundation, an organization operating out of the Alola region. Her unique brand of Science and amorality clearly marks her as The Rani.
Lusamine displays a very acute mind, and has perfect IVs for all of her pokemon, only The Rani could pull off such a feat.
Evil Creatures Edit
Lusamine also has a preference for evil otherworldly beasts.  NSFW. Her preference is cleary analogous to The Rani's Tetraps.