So like I already mentioned in a comment on that save, that's what CRAY does when sparked with PSCN; it spawns/deletes its ctype in a range defined by its tmp.

It's constant because the sparkers on the left spark the CRAY that creates the LIGH beam only every other frame. That's good because LIGH spawned by CRAY exists for two frames. So in every odd frame the CRAYs spawn LIGH, then every even frame the LIGH beam stays there and the CRAYs are not activated. If they were, they'd kill the LIGH beam too early. The sparkes on the left are very cleverly built.