[quote=@Archmage MC]
[@Lugubrious] Is it safe to assume most traps on each floor ext are made by Graft? If so, think he also designed the scrooge mcduck vault? xD
[/quote]

Not at all. Each floor was designed by a guildmember and then made by them and whoever else helped, probably by donating resources. The NPCs only staff the floors. Only after getting to the new world can they actually start making stuff of their own. At that point, though, Graft would certainly peddle his traps to other Chapter Keepers. As such, the vault was either made by Light's creator, the guild leader, or whoever might have been assigned the Treasurer or Architect role in the guild.