Hmm, might it be possible for the invisible object to be "launched" like a fighter, a modedrate distance, before firing the next bolt? It wouldn't exactly be ship-to-ship, but it would create a random shockwave in the fleet.
My other idea was to use the "Change object type" action, converting the ship which was hit into an identical copy, only altered so that it posessed a lightening beam (and no other weapons). If there was a way to convert it to a friendly unit in the process, it would fire on the other ships in the fleet, after which you could have Hera re-convert it to an enemy ship of standard stock. The process would repeat, having each ship fire upon the next, and you could probably use a counter to limit the chain reaction to 5 or so.
That last thought is a bit risky, as I'm not sure you could pull it off with Hera in its semi-unfinished state, but its worth a try.
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Ethernet (n): something used to catch the etherbunny