That cleric is Lenore, whose tower in the Underdark features prominently in BG3's first act. Much like Yrre, Lenore is never seen, but learned about through item descriptions and texts found ...

Tyr excels in maintaining law and order, upholding justice with powerful law spells. Mystra, the goddess of magic, favors order, balance, and wields unmatched magical power, casting powerful ...