After spending an hour planning the raid and preparing the plan, it was finally time to carry out the raid. Yvraine used her illusion artifact in conjunction with Nefertari's Mirage Ability in order to transform several of Samiel's Undead into the appearance of the Silvermoon Elf.
A combination of Yvraine's illusion artifact together with Nefertari's Mirage Ability resulted in a basically flawless illusion of the Silvermoon Elves, which was perfect. They were extremely realistic due to the Mirage, so it couldn't be dispersed easily in case the Human Brotherhood had something in that regard, which Samiel doubted.
Artifacts or Magetech devices that were used to discern illusions, especially the high-quality ones, were extremely pricy and not something that even the 13 Gates would hand over to some of their goons because the loss of one was deep cut into the budget.