Sarastro in Mozart’s “The Magic Flute,” e.g.

BASSO

This deep-voiced role often sings the lowest male part in opera, like the villainous but wise priest in a famous 1791 work.

This clue points to a deep-voiced male opera role, specifically Sarastro, the wise high priest in Mozart’s The Magic Flute. In opera terminology, such a low, powerful voice is called a "basso" (short for basso profondo), which fits the answer. The "e.g." signals that Sarastro is just one example of this vocal type, helping solvers connect the character to the broader category.