Decide how mulato is used in your recipe: whole chile steeped/softened, ground into mole/sauce, or used as a spice rub.
Choose the closest flavor-family substitute from the list and use the listed ratio relative to mulato (start at the lower end if you’re heat-sensitive).
Toast dried chiles briefly (30–45 seconds) or warm the adobo paste so the flavor blooms, then blend with soaking liquid or broth until smooth.
Taste early: if the sauce feels too smoky, increase ancho/pasilla by 1–2 tablespoons per cup; if too sharp, add a teaspoon of brown sugar.
Proceed with cooking and re-check after simmering—mole-style flavors round out after 5–10 minutes.