Edward Buck has long displayed strong leadership skills and perseverance despite participating in some of the Covenant War's most vicious and desperate battles. Having turned down and intentionally sabotaged multiple promotions in order to remain a small-unit leader, Buck maintains contacts with former subordinates who are now highly placed in both colonial and UEG organizations.
As a former ODST, Buck has considerable combat experience, but his most valuable to Fireteam Osiris is as a joint-forces liaison and advisor. Given the sensitive nature of Osiris' missions his current assignment is engineered to to groom him for a greater role within the Spartan branch.
As of August 2558, Spartan Buck completed 188 military operations [49 full campaigns] in his combined ODST and Spartan career. Since Buck's recruitment into the Spartan branch in 2524 he led FireteamAlpha-Nine, and later served as temporary Spartan Commander aboard the UNSC Meriwether Lewis, until his transfer to Infinity and Fireteam Osiris.