As is well-known by now, Born of the Gods and Journey into Nyx will feature a total of ten two-color minor gods, with the allied ones and enemy ones presumably mixed (since there's no strong theme for one kind of combination or the other in this block) and divided five per set. Two of those enemy-color gods are Iroas in red and white and Kruphix in green and blue, and they are joined by, among others, Pharika of black and green, who is at once among the kindest and the deadliest of the gods.
Pharika - whose dual nature is emphasized quite well by her name, which comes from the Greek "pharmakon," which means both "medicine" and "poison," is the god of disease and healing. As far as what Greek god inspired her, she seems to be a quite sinister version of Asclepius, the deified mortal doctor. She appears to be the patroness of Gorgons, such as Pharika's Mender, and her statue in the artwork of Pharika's Cure seems to imply she takes the form of one. Her primary specialty seems to be transmogrifying venoms into healing potions and vice-versa, as demonstrated by the flavor texts of the cards named after her:
"The venom cleanses the sickness from your body, but it will not be pleasant, and you may not survive. Pharika's blessings are fickle."
—Solon, acolyte of Pharika
"The direst venom becomes a panacea under Pharika's guidance. I bring it to the worthy, clinging at the edge of the abyss."
Pharika's mechanical focus on life and death could mean any number of things - lifelink and deathtouch, regeneration, or indeed recurring cards from graveyard to hand.
Though there are no portions of the lore that record her interactions with the rest of the pantheon, it's safe to say she and her followers are shunned, and looked on as a necessary evil, by almost every other god. Purphoros, Heliod, and Iroas likely revile her for her underhandedness; Erebos is not to take kindly to the disturbance of the dead in his realm, nor to it filling with mortals over-quickly; and even raging Mogis probably looks on her as a coward who is afraid to kill people the proper way.