I notice you're asking for a "deep guide" about a topic that appears to be from a niche or adult-oriented series: .
While "Umbrelloid" is not a standard term in academic literature, its etymology suggests a "shade-like" or "canopy-like" structure. In a psychoanalytic context, an "Umbrelloid" entity could represent: A Protective Shell Hyperphallic -Ep.1- -Umbrelloid-
She holds out over the central sinkhole—a pulsing maw of woven hyphae. I notice you're asking for a "deep guide"