I'm curious as well since before the trailer I was under the impression that Glaciem and Igneas were akin to Light/Shadow magic in the first game. I don't know if Alucard will actually physically wield the Void Sword while he uses the Chaos-infused Crissaegrim in a separate slot. I also wonder if Alucard will still keep his Void/Chaos powers after putting back the relics to where they belong, or if his powers are separate from the power-ups he gives back to Dracul.
Anyway, I'm just hoping that Alucard gets to access some of his MoF abilities like the Demonic Wings, Shadow Claws, Wolf Form (which looks to be replaced by Wolf Within unfortunately) and Mist. It's unlikely, but seeing the Wolf Form wielding Crissaegrim while supercharged with Chaos/Shadow Magic would be so cool. I was even hoping Alucard would find his Light/Shadow medallions from MoF, but that would have made his vampiric abilities redundant I suppose.