I think the correct answer would be
... empieza de repente como si fuera para representar
You can't actually say "como si fuera representar", the way to say it is:
... empieza de repente como si fuera a representar un eclipse.
This second one would mean something closer to the first one (like if it was to represent and eclipse). I think you could go with both prepositions,
a and there would be no practical difference.
You could also use:
... empieza de repente como si representara
The subjuntivo is a verb tense that can show purpose, wish, uncertainty or doubt, among other things, so I think works well for this transaltion.