Aspen
"I agree with Willow. They always called me the "smart one", but I guess they didn't account for the fact that smarts means one can think for themselves."
Aspen was the seventh of what was to be many, many more clones. The first batch he was a part of with his sister, number III. was not very lucky - out of 10, only the two of them survived. The two of them formed a very close bond.
Together with his sister, the two survived the grueling training that killed all their fellow clones, and as such, they are remarkably dangerous killers. However, they rely on each other for this strength, which is a pretty big weak point.
They are sent to secure a couple runaways, a mission that seems like a barely veiled suicide mission...
His title "lucky seven" has to do with the fact that he was extremely prolific and smart from a young age - where Willow is the strategist, he is the well of knowledge that supports her ingenuity.
However, just like his sister, he is also considered a "wild card", mainly for the fact that his intellect brought a side effect they weren't expecting - a personality. The two of them are considered failures exactly for this reason. The two of them ended up with their own interpretations of who they are.
Aspen is rather soft-spoken, but he is vicious. He is just as dangerous as his sister if left unattended, so don't let his outward appearance fool you. The two of them are strongest when working together.
( sister )
His older sister, Willow. They are identical clones but consider each other actual family - despite their untraditional entry into this world.
Their close relationship started early, but it only solidified when they were the only ones left - they only have each other to rely on, and they are not willing to give up the other for anything.
Aspen knows that they are probably expected to die on their mission, and he is considering turning his back. Anything to save Willow.
( target, eventual adoptive parent? )
One of the people that Aspen and Willow has been tasked with chasing down. All they know is that she took the Ice Maiden and ran with her.
The twins are about ready to defect, though, and once they realize that Dina hates the organisation just as much as they do, they end up allying themselves with her.
( target, evnetual adoptive sibling? )
Eve is disparagingly known as the "ice maiden" in the organisation, and that's all Willow and Aspen were ever told; they don't get much information as they are considered pretty low on the ladder as their younger clones take over.
They know she is dangerous, and when they get the missive to "eliminate" her, it's obvious that the plan is for them to get caught up in her ice storm and perish.