Instructions:

Pick Garrus and choose armor/skin that gives boost for weapon damage.

Level him up and pick every skill that gives boost for assault rifles.

Then give him N7 Typhoon LMG and slap an extended barrel (for extra DMG) and a Magazine upgrade (for maximum amount of DAKKA) to that bitch. Remember to upgrade the weapon itself on Normandy!

Finally, just apply AP rounds on his gun and let him ascend past the gates of Valhalla and take his place among the kings of Asgard.

Note: You'll need the Groundside Resistance Pack DLC to acquire the N7 Typhoon in singleplayer.

Song used: "Giuseppe Verdi: Messa da Requiem - Dies iraes"