I wonder if Summoner might be an interesting choice for something like this. I'm trying to avoid Reaper and Sage specifically because they're introduced in EW, so they seem too "convenient" or obvious a choice. Summoner is matched with Scholar, with has ties to Sharlayan, and also is the closest thing we have to present-day "creation" magic (even if it's not quite that), which presents a good tie-in to the Ancients. I also don't think there's any Summoner amongst our adventuring Scions, so it would be a sensible class for the WoL to use as it brings something unique to the group.