User blog comment:Miskos3/Fairy Tail Chapter 334: Sin and Sacrifice, Review/@comment-202.156.10.11-20130607160115/@comment-4829046-20130611063016

How about this then, perhaps in order to pass through each other, the beams need to sync with each other when they hit, otherwise they simply clash. I imagined scenarios where the beams do indeed pass through each other under right conditions.

Also most alien-based games and media have energy-based weaponry that take the form of a sword with a force-field like thing for a blade. How about that then? If they are force-field type in orgin, then it makes sense for two of them to bounce of each other instead of connecting.