Likely a leftover feature from debug testing, a code could be activated in earlier versions of the game that can instantly kill the characters by holding ZL/ZR/L/R/X/D-Pad Down for around 5 seconds. It could also be activated in the middle of cutscenes or while talking to NPCs. This code was removed in version 2.1.0 of the game.
It is possible to get out of bounds in Temperantia into the massive barren wasteland north of the game's map. This giant stretch of land is fully rendered and has collision-detection allowing you to walk as far as you want, but no in-game events happen in this location leaving the reason to why it was included at all unknown.