I think this might be a lawyer-friendly reference to Fire Emblem. Luna and Sol are two High-level combat skills from that franchise. And the two together at once is another high-level skill called Aether which is generally a skill only Lords or other Main characters in the series get to use.
Of course, it could just be an astrological reference as well but the fact that he uses them as blades in the next strip leads me is what makes me think it might be a reference to Fire Emblem instead.
Naming weaponry after astrological phenomena is as old as weaponry itself, so I'd say it's probably best to presume that rather than a more peculiar reference.
