Objective
To clarify when, in what kind of context 'hubo' is used.
Background
Stemmed from Past passive form of "Godzilla ha comido el hombre".
Looks related to ¿Cómo se usa el antepretérito?.
Issue
In my current understanding, 'haber + past participle' = perfect, indicating something has/had happened/completed and the state remains now/then.
However, mechanically applying 'haber -> hubo' to the sentence (1) to create a past form as (2) looks not exactly correct as Spanish.
- El hombre ha sido comido por Godzilla.
- El hombre hubo sido comido por Godzilla.
I understand to sound like "Spanish", it should be below but this is for the sake of learning.
- (El) Godzilla se ha comido al hombre. (El is required?)
Question
Why this 'hubo + past particle' can be strange/unusual (or incorrect?) in Spanish?
Is it because 'hubo' would be regarded as the past form of 'hay' indicating 'there was'?
What makes the native Spanish speakers think 'strange'?
And where/when 'hubo' should be used?