1) So in the Realms, everyone sane believes in all the gods, wherefore they swear by either the deities they most revere, or that anger them the most. So for Mystra, THE goddess (of magic), the equivalent oath would be: “Elminster Farruking Aumar!” #realmslore

2) For Chauntea, it would be “Janness Farruking Harvestmother!” For Bane: “Iyachtu Farruking Xvim!” For Shar: “Dazhra Farruking Headless!” …and so on. #realmslore

3) However, in the Realms, the style of holy swearing is more often “By the [attribute] of [deity]” So: “By the Unholy Madness of Cyric!” or “By The Unfailing Lash of Loviatar!” or “By the Blessed Blood of Ilmater!” #realmslore