If you're looking for someone to actually be the first to complete a brand new raid with new mechanics, you'll be looking for people that have completed the raid with no prior knowledge. You'll want a skilled survivor and creative thinker. It doesn't matter how well you can complete the same thing over and over after its been spelled out to you. You'll want someone who can come up with new ways of beating things. You'll want a person with multiple classes that completed the raid beginning to end in different raid parties (i.e. filling different roles each time). You'll want a person that finished in the first week of the raid without having an experienced raid member telling them how to do it. You'll want a team player that is flexible and versatile, more so than just someone who can follow a how-to guide.