X-Connections
Although there was misinformation to Scully and Doggett about super soldiers being created by the US government, super soldiers or alien replacements were actually created by the Colonists. Super soldiers have a metal spine just below the hairline on the back of their neck. They can not be killed in any conventional way as proven by Billy Miles when he came back to life after being crushed in a garage compactor. (Essence) The only way to kill them is a metal alloy. (Trust No 1)
There are many super soldiers living amongst humans as evidenced in Existence. It is unknown what the Colonists have planned for their human-alien replacements.
X-Connections
Characters
Aliens