"Riddle."

So, maybe two things brought this strip about: first, an old post about two stoners contemplating lightsaber fights, with one asking why Jedis or Sith don't use the Force to boop! Switch their opponent's lightsaber off mid-fight. Because that would be a dick move, even for a Sith? (Deep, nerdy sigh: I don't think most Force-users are capable of that kind of focus in the middle of a duel; it would be like trying to do complex equations during a fight. That or "keeping your lightsaber from being switched off mid-fight" is like a day one class.) And while prop lightsabers are usually big enough to accommodate batteries, or a plastic blade; in-story aren't they relatively thinner? Whereas in other media, like comics, a legally-distinct-from-a-lightsaber weapon usually looks like a good-sized Maglite. 

Dane's photon sword maybe hasn't been seen in comics for a while--like since he came back from the Ultraverse? So far I don't think there's been any in-story reason for him not to have it, or to have not built another one if he left it in the Ultraverse. My first thought was he probably could, unless it required materials or components he couldn't easily get anymore--stupid chip shortage! I haven't seen an Official Handbook of the Marvel Universe diagram, so for all I know it could take plutonium, vibranium, dilithium, Kryptonite, and crack to build a photon sword. (To the tune of Queens of the Stone Age "Feel Good Hit of the Summer.") We've linked back to OAFE's Black Knight review a couple times, but as they point out, the blade on the Black Knight's photon sword is not removable, nor did Hasbro supply an off version. If you look real close at it, you can see the hilt has a little peg, that the blade fits on; rather than the blade having a peg that plugs into the hilt. Best guess, the plasic of the blade maybe wouldn't have supported a peg, or wouldn't cast properly? 

In-continuity, Dane had "the Sword of Light" and "Shield of Night" for a while: I can picture the Shield, I think one of the earlier Black Knight figures has it. Those were from Merlin, or a Merlin, anyway: it feels like there's a couple different versions of him kicking around the 616, who knows what you'll get? Two different versions appeared in Excalibur; that Merlin was eventually revealed as a manipulative dick and then never seen again, at least in that book. Or, there's the friendly grouch of Iron Man #250: England seems to be actively working against his efforts to save it, but still seems better than current England? I haven't seen the Black Knight's Merlin, he could be one of those or so different he's basically another guy entirely. But, I'm thinking of that seemingly brief stretch, where Captain America had just got his proper vibranium shield back, but still had his replacement photonic shield gizmo: why wouldn't you keep both? That thing can't be too heavy...I could see Cap deciding that keeping it charged was too much of a pain, didn't want to get into a situation where it failed maybe. For Dane, it could be the Ebony Blade exerting some influence: thou shalt have no swords before me. 

Oh, and "the riddle of steel" is almost a Zen koan, and might be if you want it to be; but it's from the Conan the Barbarian movie; and has nothing to do with anything!