Battle Group Phi
From Halopedia, the Halo wiki
During an engagement with a Covenant armored force near Harvest's northern pole, where several M808B Scorpions and the trialed HRUNTING Mark III [B] Cyclops were used. The Battle group was also assisted by SPARTAN-II supersoldier Keiichi-047 who charged the Covenant's position, killing several Sangheili and Unggoy with his AIE-486H machine gun, who upon reaching the Covenant's main line he hijacked a Wraith and used it against the remaining Covenant forces.
Captain Jenkins later in the day in BATTLE GROUP PHI DEBRIEF-0820039 debriefed to Captain James Cutter on the earlier engagement saying that they were wiping up the remnants of that group of Covenant in the area, and noting it was unusual that the Covenant were committing forces without any logistical support.