"Seizon senryaku!" (or "Survival strategy!"). It's still unknown how this magic works, but we know that can "resuscitate" someone. In the case of Himari, only for a period of time and by paying a "price". Spoiler: in episode 23 Sanetoshi uses this spell on Masako (who died to save Kanba), in order to demonstrate him that he could save Himari.
Spoiler: "Let's share the fruit of fate". It's the spell that Momoka's diary contained. It can "transfer someone's fate" by paying an equal price (from a little injury to burning up totally). Ringo discovered it thanks to the gift of Double H to Himari (the idols said in fact that it was the favourite phrase of their friend). It is also worthy to mention that Kanba, when sharing his apple with Shoma when they were children, unwittingly spoke the spell, which then allowed Shoma to live by splitting his life.