Ken Akamatsu
He also forms a probationary contract (pactio) with Theo and is awarded the "Mile Vincula" (The Thousand Bonds), a passport-holder-like artifact that allows him to freely use his partners' artifacts. Ken Akamatsu has noted, however, that Negi cancelled the contract after his match with Jack Rakan was finished; he should no longer be able to use his exceedingly rare artifact.