Lust is the 1st formally introduced homunculus in the Full Metal Alchemist series.
Following The ElricsEdit
Lust initially appears controlling Father Cornello, after she gave him a weak stone to lure the Elrics & other skilled alchemists searching for it in the original anime. She was later revealed to have been studying Majhal's potential when originally noticing the brothers & influences Mugear into creating imitation red stones with red water in Xenotime after asking Envy to fill in for Cornello.
She appears before Marcoh & threatens him should he not reveal the information he gave the Elrics about his research. After he impales her with alchemy, Lust regenerates & forces the doctor to reveal the location of his research by threatening a nearby maid's life. When searching Central Library for his notes, she finds Scar, who she then fights setting the library on fire in the process.
Following Greed's Death she meets up with Lujon again, & started to remember things from when she was alive. She gave Lujon a stone just like Cornello after Envy infected his village with disease that turns the body to stone & taught him alchemy. Lust grew close to him because he was just like Scar's Brother, the man who attempted to bring her back to life. After killing Lujon she returns to Liore & there confronts Edward Elric during his fight with Scar, who she then started supporting in the hopes of creating the stone.
Death & BetrayalEdit
After Scar's death & the creation of the philosopher's stone she congratulates the Elric Brothers & reveals that they will be chased down now that they have it before she leaves. She is then apprehended by the other homunculi for disobeying orders in Liore. While with Sloth & Wrath she decided to side with Edward Elric, believeing that he would be more likely to make her human than her master. She was killed by Wrath while helping the Elric Brothers after forgetting he could use alchemy to activate the seal.
Brotherhood & Manga AdaptationEdit
Lust is depicted similarly, although rather than trying to create the philosopher's stone so she can be human, she is carrying out Father's plans. Lust eventually starts dating Jean Havoc while taking the name Solaris in order to get information on Mustang. While doing this she & Envy came up with plan to get Mustang to stop looking into how they killed Hughes & framed Maria Ross. She was repeatedly burned to death by Mustang underneath 3rd Laboratory by Roy Mustang.