Most of episode 34 of Ushio to Tora (2015-16 version) is devoted to revealing Tora's past. We learn that his attendant, named Rama, had an older sister. Twice, Rama's sister mentions (perhaps half in jest) how she should like to take refuge inside Shagaksha's mouth should battle ensue.
There's clearly some sort of mythological allusion going on here, and it's almost certainly something either Indian (since they quite apparently are from there) or Japanese in nature, but I can't pin it down. What's going on here?
(Initially, my thought was that this was going to turn out to be some sort of weird irony and Shagaksha would end up eating her, but that didn't happen, which is why I suspect there's an allusion I'm missing.)
