Banshee-44 takes the Grenade Launcher from you and applies the catalyst.

"I had to do some real research into Hive stuff to figure out how to get it just right," he says.

"Saw some old names," he mutters. "Stirred up some old memories."

Work complete, he hands the weapon back to you with a wink.

"If you use that thing on Crota, tell him Banshee sent you."