The Forever Knights were a group that featured in Ben 10.
The Forever Knights were a secret society that were formed during the Middle Ages who were dedicated in their goal of collecting alien technology. They were formed after encountering an alien dragon from space who had been captured by the organization. In hopes of slaying it, they sought the acquisition of alien technology in order to find a means to kill it.
The organization lived a secret life on Earth and had remained hidden for thousands of years. They tended to dress up in middle clothing which matches their knight style appearance. Despite the use of seemingly primitive weapons, the Forever Knights make use of powerful alien technology to enhance their combat capabilities.
Their goal was the simple acquisition of alien technology and were noted to engage in smuggling operations with other alien races in order to get new weapons to add to their arsenal. They were also noted to capture any aliens that operated on Earth whereupon the subject was studied and dissected. Any Humans that were prsent with them were diposed of.