Huh. I suppose Lavos could have "absorbed" the sword, but why?
I always assumed that after Lavos was summoned, the sword was supposed to be like Schala's original pendant; lost to the ages (until someone finally found it). But, as asked above, why would Lavos have bothered to absorb the sword assuming it wasn't lost (and, more importantly, could it have?)
As for Magus' weapon, I assume that we are talking about the scythe that he attacked Lavos with (and the one that produced that fun glow that for a moment makes it look like he dramatically cut off Lavos' "lead"), correct? Is there any indication that this is anything other than just a random blade? Doesn't seem like this could be the Masamune, as why would Magus plot to raise Lavos just to hope to find a weapon there? His plans would have presumably included making sure he had a weapon (still might be made of dreamstone, I suppose, as he could have had access to the laboratories of the three gurus). If Dreamstone is a conduit for power, then that might explain the seeming power drain that Magus undergoes a few seconds after his attack.